diff --git a/src/drawing/drawing.h b/src/drawing/drawing.h
index 63c37bf508..18ed4407bf 100644
--- a/src/drawing/drawing.h
+++ b/src/drawing/drawing.h
@@ -87,6 +87,15 @@ enum {
 	// REMAP_2_PLUS = REMAP 3
 };
 
+enum {
+	INSET_RECT_FLAG_FILL_GREY = (1 << 2), // 0x04
+	INSET_RECT_FLAG_BORDER_NONE = (1 << 3), // 0x08
+	INSET_RECT_FLAG_FILL_NONE = (1 << 4), // 0x10
+	INSET_RECT_FLAG_BORDER_INSET = (1 << 5), // 0x20
+	INSET_RECT_FLAG_FILL_DONT_LIGHTEN = (1 << 6), // 0x40
+	INSET_RECT_FLAG_FILL_MID_LIGHT = (1 << 7), // 0x80
+};
+
 typedef struct rct_g1_header {
 	uint32 num_entries;
 	uint32 total_size;
@@ -122,6 +131,10 @@ typedef struct rct_palette {
 
 #define PALETTE_TO_G1_OFFSET_COUNT 144
 
+#define INSET_RECT_F_30 (INSET_RECT_FLAG_BORDER_INSET | INSET_RECT_FLAG_FILL_NONE)
+#define INSET_RECT_F_60 (INSET_RECT_FLAG_BORDER_INSET | INSET_RECT_FLAG_FILL_DONT_LIGHTEN)
+#define INSET_RECT_F_E0 (INSET_RECT_FLAG_BORDER_INSET | INSET_RECT_FLAG_FILL_DONT_LIGHTEN | INSET_RECT_FLAG_FILL_MID_LIGHT)
+
 #define MAX_SCROLLING_TEXT_MODES 38
 
 extern sint16 gCurrentFontSpriteBase;
@@ -179,7 +192,7 @@ void gfx_draw_line_software(rct_drawpixelinfo *dpi, int x1, int y1, int x2, int
 
 // rect
 void gfx_fill_rect(rct_drawpixelinfo *dpi, int left, int top, int right, int bottom, int colour);
-void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short right, short bottom, int colour, short _si);
+void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short right, short bottom, int colour, uint8 flags);
 
 // sprite
 bool gfx_load_g1();
diff --git a/src/drawing/rect.c b/src/drawing/rect.c
index 444aa6dbbd..8af39b0328 100644
--- a/src/drawing/rect.c
+++ b/src/drawing/rect.c
@@ -31,17 +31,10 @@
  * colour (ebp)
  * flags (si)
  */
-void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short right, short bottom, int colour, short flags)
+void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short right, short bottom, int colour, uint8 flags)
 {
 	uint8 shadow, fill, hilight;
 
-	// Flags
-	int no_border, no_fill, pressed;
-
-	no_border = 8;
-	no_fill = 0x10;
-	pressed = 0x20;
-
 	if (colour & 0x180) {
 		if (colour & 0x100) {
 			colour = NOT_TRANSLUCENT(colour);
@@ -51,16 +44,16 @@ void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short ri
 
 		colour = colour | 0x2000000; //Transparent
 
-		if (flags & no_border) {
+		if (flags & INSET_RECT_FLAG_BORDER_NONE) {
 			gfx_fill_rect(dpi, left, top, right, bottom, colour);
-		} else if (flags & pressed) {
+		} else if (flags & INSET_RECT_FLAG_BORDER_INSET) {
 			// Draw outline of box
 			gfx_fill_rect(dpi, left, top, left, bottom, colour + 1);
 			gfx_fill_rect(dpi, left, top, right, top, colour + 1);
 			gfx_fill_rect(dpi, right, top, right, bottom, colour + 2);
 			gfx_fill_rect(dpi, left, bottom, right, bottom, colour + 2);
 
-			if (!(flags & no_fill)) {
+			if (!(flags & INSET_RECT_FLAG_FILL_NONE)) {
 				gfx_fill_rect(dpi, left+1, top+1, right-1, bottom-1, colour);
 			}
 		} else {
@@ -70,12 +63,12 @@ void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short ri
 			gfx_fill_rect(dpi, right, top, right, bottom, colour + 1);
 			gfx_fill_rect(dpi, left, bottom, right, bottom, colour + 1);
 
-			if (!(flags & no_fill)) {
+			if (!(flags & INSET_RECT_FLAG_FILL_NONE)) {
 				gfx_fill_rect(dpi, left+1, top+1, right-1, bottom-1, colour);
 			}
 		}
 	} else {
-		if (flags & 0x80) {
+		if (flags & INSET_RECT_FLAG_FILL_MID_LIGHT) {
 			shadow	= ColourMapA[colour].dark;
 			fill	= ColourMapA[colour].mid_light;
 			hilight	= ColourMapA[colour].lighter;
@@ -85,18 +78,18 @@ void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short ri
 			hilight	= ColourMapA[colour].lighter;
 		}
 
-		if (flags & no_border) {
+		if (flags & INSET_RECT_FLAG_BORDER_NONE) {
 			gfx_fill_rect(dpi, left, top, right, bottom, fill);
-		} else if (flags & pressed) {
+		} else if (flags & INSET_RECT_FLAG_BORDER_INSET) {
 			// Draw outline of box
 			gfx_fill_rect(dpi, left, top, left, bottom, shadow);
 			gfx_fill_rect(dpi, left + 1, top, right, top, shadow);
 			gfx_fill_rect(dpi, right, top + 1, right, bottom - 1, hilight);
 			gfx_fill_rect(dpi, left + 1, bottom, right, bottom, hilight);
 
-			if (!(flags & no_fill)) {
-				if (!(flags & 0x40)) {
-					if (flags & 0x04) {
+			if (!(flags & INSET_RECT_FLAG_FILL_NONE)) {
+				if (!(flags & INSET_RECT_FLAG_FILL_DONT_LIGHTEN)) {
+					if (flags & INSET_RECT_FLAG_FILL_GREY) {
 						fill = ColourMapA[COLOUR_BLACK].light;
 					} else {
 						fill = ColourMapA[colour].lighter;
@@ -111,8 +104,8 @@ void gfx_fill_rect_inset(rct_drawpixelinfo* dpi, short left, short top, short ri
 			gfx_fill_rect(dpi, right, top, right, bottom - 1, shadow);
 			gfx_fill_rect(dpi, left, bottom, right, bottom, shadow);
 
-			if (!(flags & no_fill)) {
-				if (flags & 0x04) {
+			if (!(flags & INSET_RECT_FLAG_FILL_NONE)) {
+				if (flags & INSET_RECT_FLAG_FILL_GREY) {
 					fill = ColourMapA[COLOUR_BLACK].light;
 				}
 				gfx_fill_rect(dpi, left+1, top+1, right-1, bottom-1, fill);
diff --git a/src/interface/chat.c b/src/interface/chat.c
index 40a8e09b65..bb814a4729 100644
--- a/src/interface/chat.c
+++ b/src/interface/chat.c
@@ -119,9 +119,9 @@ void chat_draw(rct_drawpixelinfo * dpi)
 
 		gfx_set_dirty_blocks(_chatLeft, _chatTop - 5, _chatRight, _chatBottom + 5); //Background area + Textbox
 		gfx_fill_rect(dpi, _chatLeft, _chatTop - 5, _chatRight, _chatBottom + 5, 0x2000000 | 51); //Opaque gray background
-		gfx_fill_rect_inset(dpi, _chatLeft, _chatTop - 5, _chatRight, _chatBottom + 5, chatBackgroundColor, 0x10);
-		gfx_fill_rect_inset(dpi, _chatLeft + 1, _chatTop - 4, _chatRight - 1, _chatBottom - inputLineHeight - 6, chatBackgroundColor, 0x20);
-		gfx_fill_rect_inset(dpi, _chatLeft + 1, _chatBottom - inputLineHeight - 5, _chatRight - 1, _chatBottom + 4, chatBackgroundColor, 0x20); //Textbox
+		gfx_fill_rect_inset(dpi, _chatLeft, _chatTop - 5, _chatRight, _chatBottom + 5, chatBackgroundColor, INSET_RECT_FLAG_FILL_NONE);
+		gfx_fill_rect_inset(dpi, _chatLeft + 1, _chatTop - 4, _chatRight - 1, _chatBottom - inputLineHeight - 6, chatBackgroundColor, INSET_RECT_FLAG_BORDER_INSET);
+		gfx_fill_rect_inset(dpi, _chatLeft + 1, _chatBottom - inputLineHeight - 5, _chatRight - 1, _chatBottom + 4, chatBackgroundColor, INSET_RECT_FLAG_BORDER_INSET); //Textbox
 	}
 	
 	int x = _chatLeft + 5;
diff --git a/src/interface/viewport.c b/src/interface/viewport.c
index 52eeaa11d6..2df05ab853 100644
--- a/src/interface/viewport.c
+++ b/src/interface/viewport.c
@@ -665,7 +665,7 @@ void viewport_render(rct_drawpixelinfo *dpi, rct_viewport *viewport, int left, i
 
 #ifdef DEBUG_SHOW_DIRTY_BOX
 	if (viewport != g_viewport_list){
-		gfx_fill_rect_inset(dpi, l, t, r-1, b-1, 0x2, 0x30);
+		gfx_fill_rect_inset(dpi, l, t, r-1, b-1, 0x2, INSET_RECT_F_30);
 		return;
 	}
 #endif
diff --git a/src/interface/widget.c b/src/interface/widget.c
index d9d32c4cbf..3a631a9424 100644
--- a/src/interface/widget.c
+++ b/src/interface/widget.c
@@ -194,7 +194,7 @@ static void widget_frame_draw(rct_drawpixelinfo *dpi, rct_window *w, int widgetI
 	int b = w->y + widget->bottom;
 
 	//
-	int press = (w->flags & WF_10 ? 0x80 : 0);
+	uint8 press = (w->flags & WF_10 ? INSET_RECT_FLAG_FILL_MID_LIGHT : 0);
 
 	// Get the colour
 	uint8 colour = w->colours[widget->colour];
@@ -263,14 +263,14 @@ static void widget_button_draw(rct_drawpixelinfo *dpi, rct_window *w, int widget
 	int b = w->y + widget->bottom;
 
 	// Check if the button is pressed down
-	int press = widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex) ? 0x20 : 0;
+	uint8 press = widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex) ? INSET_RECT_FLAG_BORDER_INSET : 0;
 
 	// Get the colour
 	uint8 colour = w->colours[widget->colour];
 
 	if (widget->image == -2) {
 		// Draw border with no fill
-		gfx_fill_rect_inset(dpi, l, t, r, b, colour, press | 0x10);
+		gfx_fill_rect_inset(dpi, l, t, r, b, colour, press | INSET_RECT_FLAG_FILL_NONE);
 		return;
 	}
 
@@ -346,12 +346,12 @@ static void widget_flat_button_draw(rct_drawpixelinfo *dpi, rct_window *w, int w
 	if (widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex)) {
 		if (widget->image == -2) {
 			// Draw border with no fill
-			gfx_fill_rect_inset(dpi, l, t, r, b, colour, 0x20 | 0x10);
+			gfx_fill_rect_inset(dpi, l, t, r, b, colour, INSET_RECT_FLAG_BORDER_INSET | INSET_RECT_FLAG_FILL_NONE);
 			return;
 		}
 
 		// Draw the border with fill
-		gfx_fill_rect_inset(dpi, l, t, r, b, colour, 0x20);
+		gfx_fill_rect_inset(dpi, l, t, r, b, colour, INSET_RECT_FLAG_BORDER_INSET);
 	}
 
 	// Draw image
@@ -377,7 +377,7 @@ static void widget_text_button(rct_drawpixelinfo *dpi, rct_window *w, int widget
 	uint8 colour = w->colours[widget->colour];
 
 	// Border
-	int press = widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex) ? 0x20 : 0;
+	uint8 press = widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex) ? INSET_RECT_FLAG_BORDER_INSET : 0;
 	gfx_fill_rect_inset(dpi, l, t, r, b, colour, press);
 
 	// Text
@@ -482,7 +482,7 @@ static void widget_text_inset(rct_drawpixelinfo *dpi, rct_window *w, int widgetI
 	// Get the colour
 	uint8 colour = w->colours[widget->colour];
 
-	gfx_fill_rect_inset(dpi, l, t, r, b, colour, 0x60);
+	gfx_fill_rect_inset(dpi, l, t, r, b, colour, INSET_RECT_F_60);
 	widget_text(dpi, w, widgetIndex);
 }
 
@@ -506,7 +506,7 @@ static void widget_text_draw(rct_drawpixelinfo *dpi, rct_window *w, int widgetIn
 
 	int press = 0;
 	if (widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex))
-		press |= 0x20;
+		press |= INSET_RECT_FLAG_BORDER_INSET;
 
 	gfx_fill_rect_inset(dpi, l, t, r, b, colour, press);
 
@@ -589,9 +589,9 @@ static void widget_caption_draw(rct_drawpixelinfo *dpi, rct_window *w, int widge
 	// Get the colour
 	uint8 colour = w->colours[widget->colour];
 
-	int press = 0x60;
+	uint8 press = INSET_RECT_F_60;
 	if (w->flags & WF_10)
-		press |= 0x80;
+		press |= INSET_RECT_FLAG_FILL_MID_LIGHT;
 
 	gfx_fill_rect_inset(dpi, l, t, r, b, colour, press);
 
@@ -633,11 +633,11 @@ static void widget_closebox_draw(rct_drawpixelinfo *dpi, rct_window *w, int widg
 	int b = w->y + widget->bottom;
 
 	// Check if the button is pressed down
-	int press = 0;
+	uint8 press = 0;
 	if (w->flags & WF_10)
-		press |= 0x80;
+		press |= INSET_RECT_FLAG_FILL_MID_LIGHT;
 	if (widget_is_pressed(w, widgetIndex) || widget_is_active_tool(w, widgetIndex))
-		press |= 0x20;
+		press |= INSET_RECT_FLAG_BORDER_INSET;
 
 	// Get the colour
 	uint8 colour = w->colours[widget->colour];
@@ -677,7 +677,7 @@ static void widget_checkbox_draw(rct_drawpixelinfo *dpi, rct_window *w, int widg
 
 	if (widget->type != WWT_24) {
 		// checkbox
-		gfx_fill_rect_inset(dpi, l, yMid - 5, l + 9, yMid + 4, colour, 0x60);
+		gfx_fill_rect_inset(dpi, l, yMid - 5, l + 9, yMid + 4, colour, INSET_RECT_F_60);
 
 		// fill it when checkbox is pressed
 		if (widget_is_pressed(w, widgetIndex)) {
@@ -718,7 +718,7 @@ static void widget_scroll_draw(rct_drawpixelinfo *dpi, rct_window *w, int widget
 	uint8 colour = w->colours[widget->colour];
 
 	// Draw the border
-	gfx_fill_rect_inset(dpi, l, t, r, b, colour, 0x60);
+	gfx_fill_rect_inset(dpi, l, t, r, b, colour, INSET_RECT_F_60);
 
 	// Inflate by -1
 	l++;
@@ -780,17 +780,17 @@ static void widget_hscrollbar_draw(rct_drawpixelinfo *dpi, rct_scroll *scroll, i
 	gfx_fill_rect(dpi, l + 10, t + 8, r - 10, t + 8, ColourMapA[colour].lighter);
 
 	// Left button
-	gfx_fill_rect_inset(dpi, l, t, l + 9, b, colour, (scroll->flags & HSCROLLBAR_LEFT_PRESSED ? 0x20 : 0));
+	gfx_fill_rect_inset(dpi, l, t, l + 9, b, colour, (scroll->flags & HSCROLLBAR_LEFT_PRESSED ? INSET_RECT_FLAG_BORDER_INSET : 0));
 	gfx_draw_string(dpi, (char*)BlackLeftArrowString, 0, l + 1, t);
 
 	// Thumb
 	gfx_fill_rect_inset(dpi,
 		max(l + 10, l + scroll->h_thumb_left - 1), t,
 		min(r - 10, l + scroll->h_thumb_right - 1), b,
-		colour, (scroll->flags & HSCROLLBAR_THUMB_PRESSED ? 0x20 : 0));
+		colour, (scroll->flags & HSCROLLBAR_THUMB_PRESSED ? INSET_RECT_FLAG_BORDER_INSET : 0));
 
 	// Right button
-	gfx_fill_rect_inset(dpi, r - 9, t, r, b, colour, (scroll->flags & HSCROLLBAR_RIGHT_PRESSED ? 0x20 : 0));
+	gfx_fill_rect_inset(dpi, r - 9, t, r, b, colour, (scroll->flags & HSCROLLBAR_RIGHT_PRESSED ? INSET_RECT_FLAG_BORDER_INSET : 0));
 	gfx_draw_string(dpi, (char*)BlackRightArrowString, 0, r - 6, t);
 }
 
@@ -806,17 +806,17 @@ static void widget_vscrollbar_draw(rct_drawpixelinfo *dpi, rct_scroll *scroll, i
 	gfx_fill_rect(dpi, l + 8, t + 10, l + 8, b - 10, ColourMapA[colour].lighter);
 
 	// Up button
-	gfx_fill_rect_inset(dpi, l, t, r, t + 9, colour, (scroll->flags & VSCROLLBAR_UP_PRESSED ? 0x20 : 0));
+	gfx_fill_rect_inset(dpi, l, t, r, t + 9, colour, (scroll->flags & VSCROLLBAR_UP_PRESSED ? INSET_RECT_FLAG_BORDER_INSET : 0));
 	gfx_draw_string(dpi, (char*)BlackUpArrowString, 0, l + 1, t - 1);
 
 	// Thumb
 	gfx_fill_rect_inset(dpi,
 		l, max(t + 10, t + scroll->v_thumb_top - 1),
 		r, min(b - 10, t + scroll->v_thumb_bottom - 1),
-		colour, (scroll->flags & VSCROLLBAR_THUMB_PRESSED ? 0x20 : 0));
+		colour, (scroll->flags & VSCROLLBAR_THUMB_PRESSED ? INSET_RECT_FLAG_BORDER_INSET : 0));
 
 	// Down button
-	gfx_fill_rect_inset(dpi, l, b - 9, r, b, colour, (scroll->flags & VSCROLLBAR_DOWN_PRESSED ? 0x20 : 0));
+	gfx_fill_rect_inset(dpi, l, b - 9, r, b, colour, (scroll->flags & VSCROLLBAR_DOWN_PRESSED ? INSET_RECT_FLAG_BORDER_INSET : 0));
 	gfx_draw_string(dpi, (char*)BlackDownArrowString, 0, l + 1, b - 9);
 }
 
@@ -1072,7 +1072,7 @@ static void widget_text_box_draw(rct_drawpixelinfo *dpi, rct_window *w, int widg
 		widgetIndex == gCurrentTextBox.widget_index;
 
 	//gfx_fill_rect_inset(dpi, l, t, r, b, colour, 0x20 | (!active ? 0x40 : 0x00));
-	gfx_fill_rect_inset(dpi, l, t, r, b, colour, 0x60);
+	gfx_fill_rect_inset(dpi, l, t, r, b, colour, INSET_RECT_F_60);
 
 	gCurrentFontSpriteBase = FONT_SPRITE_BASE_MEDIUM;
 	gCurrentFontFlags = 0;
diff --git a/src/interface/window.c b/src/interface/window.c
index d875cc7982..df0aa8e588 100644
--- a/src/interface/window.c
+++ b/src/interface/window.c
@@ -1718,7 +1718,7 @@ void window_draw_widgets(rct_window *w, rct_drawpixelinfo *dpi)
 	//todo: something missing here too? Between 006EC32B and 006EC369
 
 	if (w->flags & WF_WHITE_BORDER_MASK) {
-		gfx_fill_rect_inset(dpi, w->x, w->y, w->x + w->width - 1, w->y + w->height - 1, 2, 0x10);
+		gfx_fill_rect_inset(dpi, w->x, w->y, w->x + w->width - 1, w->y + w->height - 1, 2, INSET_RECT_FLAG_FILL_NONE);
 	}
 }
 
diff --git a/src/windows/editor_bottom_toolbar.c b/src/windows/editor_bottom_toolbar.c
index 6dfc9fc46c..5ffbb53f6d 100644
--- a/src/windows/editor_bottom_toolbar.c
+++ b/src/windows/editor_bottom_toolbar.c
@@ -463,7 +463,7 @@ void window_editor_bottom_toolbar_paint(rct_window *w, rct_drawpixelinfo *dpi)
 				window_editor_bottom_toolbar_widgets[WIDX_PREVIOUS_IMAGE].top + 1 + w->y,
 				window_editor_bottom_toolbar_widgets[WIDX_PREVIOUS_IMAGE].right - 1 + w->x,
 				window_editor_bottom_toolbar_widgets[WIDX_PREVIOUS_IMAGE].bottom - 1 + w->y,
-				w->colours[1], 0x30);
+				w->colours[1], INSET_RECT_F_30);
 		}
 
 		if ((drawPreviousButton || drawNextButton) && gS6Info.editor_step != EDITOR_STEP_ROLLERCOASTER_DESIGNER) {
@@ -472,7 +472,7 @@ void window_editor_bottom_toolbar_paint(rct_window *w, rct_drawpixelinfo *dpi)
 				window_editor_bottom_toolbar_widgets[WIDX_NEXT_IMAGE].top + 1 + w->y,
 				window_editor_bottom_toolbar_widgets[WIDX_NEXT_IMAGE].right - 1 + w->x,
 				window_editor_bottom_toolbar_widgets[WIDX_NEXT_IMAGE].bottom - 1 + w->y,
-				w->colours[1], 0x30);
+				w->colours[1], INSET_RECT_F_30);
 		}
 
 		short stateX =
diff --git a/src/windows/editor_object_selection.c b/src/windows/editor_object_selection.c
index f9959136ae..032efaf93c 100644
--- a/src/windows/editor_object_selection.c
+++ b/src/windows/editor_object_selection.c
@@ -1410,7 +1410,7 @@ static void window_editor_object_selection_scrollpaint(rct_window *w, rct_drawpi
 		if (y + 12 >= dpi->y && y <= dpi->y + dpi->height) {
 			// Draw checkbox
 			if (!(gScreenFlags & SCREEN_FLAGS_TRACK_MANAGER) && !(*listItem->flags & 0x20))
-				gfx_fill_rect_inset(dpi, 2, y, 11, y + 10, w->colours[1], 0xE0);
+				gfx_fill_rect_inset(dpi, 2, y, 11, y + 10, w->colours[1], INSET_RECT_F_E0);
 
 			// Highlight background
 			colour = 142;
diff --git a/src/windows/editor_objective_options.c b/src/windows/editor_objective_options.c
index 0909835de6..e8b5de9ca2 100644
--- a/src/windows/editor_objective_options.c
+++ b/src/windows/editor_objective_options.c
@@ -1205,7 +1205,7 @@ static void window_editor_objective_options_rides_scrollpaint(rct_window *w, rct
 			continue;
 
 		// Checkbox
-		gfx_fill_rect_inset(dpi, 2, y, 11, y + 10, w->colours[1], 224);
+		gfx_fill_rect_inset(dpi, 2, y, 11, y + 10, w->colours[1], INSET_RECT_F_E0);
 
 		// Highlighted
 		if (i == w->selected_list_item) {
diff --git a/src/windows/finances.c b/src/windows/finances.c
index e569217ccc..13c4511f0a 100644
--- a/src/windows/finances.c
+++ b/src/windows/finances.c
@@ -742,7 +742,7 @@ static void window_finances_summary_paint(rct_window *w, rct_drawpixelinfo *dpi)
 
 
 	// Horizontal rule below expenditure / income table
-	gfx_fill_rect_inset(dpi, w->x + 8, w->y + 223, w->x + 8 + 513, w->y + 223 + 1, w->colours[1], 0x20);
+	gfx_fill_rect_inset(dpi, w->x + 8, w->y + 223, w->x + 8 + 513, w->y + 223 + 1, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 
 	// Loan and interest rate
 	gfx_draw_string_left(dpi, STR_FINANCES_SUMMARY_LOAN, NULL, 0, w->x + 4, w->y + 229);
@@ -843,7 +843,7 @@ static void window_finances_financial_graph_paint(rct_window *w, rct_drawpixelin
 	);
 
 	// Graph
-	gfx_fill_rect_inset(dpi, graphLeft, graphTop, graphRight, graphBottom, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, graphLeft, graphTop, graphRight, graphBottom, w->colours[1], INSET_RECT_F_30);
 
 	// Calculate the Y axis scale (log2 of highest [+/-]balance)
 	int yAxisScale = 0;
@@ -949,7 +949,7 @@ static void window_finances_park_value_graph_paint(rct_window *w, rct_drawpixeli
 	);
 
 	// Graph
-	gfx_fill_rect_inset(dpi, graphLeft, graphTop, graphRight, graphBottom, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, graphLeft, graphTop, graphRight, graphBottom, w->colours[1], INSET_RECT_F_30);
 
 	// Calculate the Y axis scale (log2 of highest [+/-]balance)
 	int yAxisScale = 0;
@@ -1055,7 +1055,7 @@ static void window_finances_profit_graph_paint(rct_window *w, rct_drawpixelinfo
 	);
 
 	// Graph
-	gfx_fill_rect_inset(dpi, graphLeft, graphTop, graphRight, graphBottom, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, graphLeft, graphTop, graphRight, graphBottom, w->colours[1], INSET_RECT_F_30);
 
 	// Calculate the Y axis scale (log2 of highest [+/-]balance)
 	int yAxisScale = 0;
diff --git a/src/windows/game_bottom_toolbar.c b/src/windows/game_bottom_toolbar.c
index 2f56ef1d71..95447d6ae8 100644
--- a/src/windows/game_bottom_toolbar.c
+++ b/src/windows/game_bottom_toolbar.c
@@ -371,7 +371,7 @@ static void window_game_bottom_toolbar_draw_left_panel(rct_drawpixelinfo *dpi, r
 		w->x + window_game_bottom_toolbar_widgets[WIDX_LEFT_OUTSET].right - 1,
 		w->y + window_game_bottom_toolbar_widgets[WIDX_LEFT_OUTSET].bottom - 1,
 		w->colours[1],
-		48
+		INSET_RECT_F_30
 	);
 
 	x = (window_game_bottom_toolbar_widgets[WIDX_LEFT_OUTSET].left + window_game_bottom_toolbar_widgets[WIDX_LEFT_OUTSET].right) / 2 + w->x;
@@ -426,7 +426,7 @@ static void window_game_bottom_toolbar_draw_park_rating(rct_drawpixelinfo *dpi,
 	short bar_width;
 
 	bar_width = (factor * (90 + WIDTH_MOD)) / 256;
-	gfx_fill_rect_inset(dpi, x, y + 1, x + (93 + WIDTH_MOD), y + 9, w->colours[1], 48);
+	gfx_fill_rect_inset(dpi, x, y + 1, x + (93 + WIDTH_MOD), y + 9, w->colours[1], INSET_RECT_F_30);
 	if (!(colour & 0x80000000) || game_is_paused() || (gCurrentTicks & 8)) {
 		if (bar_width > 2)
 			gfx_fill_rect_inset(dpi, x + 2, y + 2, x + bar_width - 1, y + 8, colour & 0x7FFFFFFF, 0);
@@ -450,7 +450,7 @@ static void window_game_bottom_toolbar_draw_right_panel(rct_drawpixelinfo *dpi,
 		w->x + window_game_bottom_toolbar_widgets[WIDX_RIGHT_OUTSET].right - 1,
 		w->y + window_game_bottom_toolbar_widgets[WIDX_RIGHT_OUTSET].bottom - 1,
 		w->colours[1],
-		48
+		INSET_RECT_F_30
 	);
 
 	x = (window_game_bottom_toolbar_widgets[WIDX_RIGHT_OUTSET].left + window_game_bottom_toolbar_widgets[WIDX_RIGHT_OUTSET].right) / 2 + w->x;
@@ -521,7 +521,7 @@ static void window_game_bottom_toolbar_draw_news_item(rct_drawpixelinfo *dpi, rc
 		w->x + middleOutsetWidget->right - 1,
 		w->y + middleOutsetWidget->bottom - 1,
 		w->colours[2],
-		48
+		INSET_RECT_F_30
 	);
 
 	// Text
diff --git a/src/windows/guest.c b/src/windows/guest.c
index d63d806854..907ebfb57e 100644
--- a/src/windows/guest.c
+++ b/src/windows/guest.c
@@ -1331,7 +1331,7 @@ static void window_guest_stats_bars_paint(int value, int x, int y, rct_window *w
 	value *= 0x76;
 	value >>= 8;
 
-	gfx_fill_rect_inset(dpi, x + 0x3A, y + 1, x + 0x3A + 0x79, y + 9, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, x + 0x3A, y + 1, x + 0x3A + 0x79, y + 9, w->colours[1], INSET_RECT_F_30);
 
 	int blink_flag = colour & (1u << 0x1F); //0x80000000
 	colour &= ~(1u << 0x1F);
@@ -1475,7 +1475,7 @@ void window_guest_stats_paint(rct_window *w, rct_drawpixelinfo *dpi)
 	}
 
 	y += 19;
-	gfx_fill_rect_inset(dpi, x, y - 6, x + 179, y - 5, w->colours[1], 32);
+	gfx_fill_rect_inset(dpi, x, y - 6, x + 179, y - 5, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 
 	// Preferred Ride
 	gfx_draw_string_left(dpi, STR_GUEST_STAT_PREFERRED_RIDE, (void *) 0, 0, x, y);
@@ -1810,7 +1810,7 @@ void window_guest_finance_paint(rct_window *w, rct_drawpixelinfo *dpi)
 	gfx_draw_string_left(dpi, STR_GUEST_STAT_CASH_SPENT, gCommonFormatArgs, 0, x, y);
 
 	y += 20;
-	gfx_fill_rect_inset(dpi, x, y - 6, x + 179, y - 5, w->colours[1], 32);
+	gfx_fill_rect_inset(dpi, x, y - 6, x + 179, y - 5, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 
 	// Paid to enter
 	set_format_arg(0, money32, peep->paid_to_enter);
diff --git a/src/windows/multiplayer.c b/src/windows/multiplayer.c
index c776ceaa88..84dcbdde40 100644
--- a/src/windows/multiplayer.c
+++ b/src/windows/multiplayer.c
@@ -843,7 +843,7 @@ static void window_multiplayer_groups_paint(rct_window *w, rct_drawpixelinfo *dp
 
 	y += 20;
 
-	gfx_fill_rect_inset(dpi, x, y - 6, x + 310, y - 5, w->colours[1], 32);
+	gfx_fill_rect_inset(dpi, x, y - 6, x + 310, y - 5, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 
 	widget = &window_multiplayer_groups_widgets[WIDX_SELECTED_GROUP];
 	group = network_get_group_index(_selectedGroup);
diff --git a/src/windows/music_credits.c b/src/windows/music_credits.c
index 8c8c410c50..2bcc7d9f54 100644
--- a/src/windows/music_credits.c
+++ b/src/windows/music_credits.c
@@ -201,7 +201,7 @@ static void window_music_credits_scrollpaint(rct_window *w, rct_drawpixelinfo *d
 
 	// Draw the separator
 	y += 5;
-	gfx_fill_rect_inset(dpi, 4, y, 484, y+1, w->colours[1], 0x20);
+	gfx_fill_rect_inset(dpi, 4, y, 484, y+1, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 	y += 11;
 
 	for (int i = 0; i < countof(music_credits_rct2); i++) {
diff --git a/src/windows/new_ride.c b/src/windows/new_ride.c
index cfd33cca34..15f1d7cc2b 100644
--- a/src/windows/new_ride.c
+++ b/src/windows/new_ride.c
@@ -790,9 +790,9 @@ static void window_new_ride_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, i
 		// Draw flat button rectangle
 		int flags = 0;
 		if (w->new_ride.selected_ride_id == *((sint16*)listItem))
-			flags |= 0x20;
+			flags |= INSET_RECT_FLAG_BORDER_INSET;
 		if (w->new_ride.highlighted_ride_id == *((sint16*)listItem) || flags != 0)
-			gfx_fill_rect_inset(dpi, x, y, x + 115, y + 115, w->colours[1], 0x80 | flags);
+			gfx_fill_rect_inset(dpi, x, y, x + 115, y + 115, w->colours[1], INSET_RECT_FLAG_FILL_MID_LIGHT | flags);
 
 		// Draw ride image with feathered border
 		rideEntry = get_ride_entry(listItem->entry_index);
diff --git a/src/windows/news.c b/src/windows/news.c
index ba0ba0d039..54555b04ae 100644
--- a/src/windows/news.c
+++ b/src/windows/news.c
@@ -287,7 +287,7 @@ static void window_news_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, int s
 		}
 
 		// Background
-		gfx_fill_rect_inset(dpi, -1, y, 383, y + 41, w->colours[1], 0x24);
+		gfx_fill_rect_inset(dpi, -1, y, 383, y + 41, w->colours[1], (INSET_RECT_FLAG_BORDER_INSET | INSET_RECT_FLAG_FILL_GREY));
 
 		// Date text
 		set_format_arg(0, rct_string_id, DateDayNames[newsItem->day - 1]);
@@ -312,7 +312,7 @@ static void window_news_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, int s
 				const uint8 idx = 11 + w->news.var_480;
 				news_item_is_valid_idx(idx);
 				if (i == idx && w->news.var_482 == 1)
-					press = 0x20;
+					press = INSET_RECT_FLAG_BORDER_INSET;
 			}
 			gfx_fill_rect_inset(dpi, x, yy, x + 23, yy + 23, w->colours[2], press);
 
diff --git a/src/windows/park.c b/src/windows/park.c
index 5d9b21921c..ea5ceb6adb 100644
--- a/src/windows/park.c
+++ b/src/windows/park.c
@@ -1275,7 +1275,7 @@ static void window_park_rating_paint(rct_window *w, rct_drawpixelinfo *dpi)
 	gfx_draw_string_left(dpi, STR_PARK_RATING_LABEL, &gParkRating, 0, x + widget->left + 3, y + widget->top + 2);
 
 	// Graph border
-	gfx_fill_rect_inset(dpi, x + widget->left + 4, y + widget->top + 15, x + widget->right - 4, y + widget->bottom - 4, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, x + widget->left + 4, y + widget->top + 15, x + widget->right - 4, y + widget->bottom - 4, w->colours[1], INSET_RECT_F_30);
 
 	// Graph
 	x += widget->left + 22;
@@ -1392,7 +1392,7 @@ static void window_park_guests_paint(rct_window *w, rct_drawpixelinfo *dpi)
 	gfx_draw_string_left(dpi, STR_GUESTS_IN_PARK_LABEL, &gNumGuestsInPark, 0, x + widget->left + 3, y + widget->top + 2);
 
 	// Graph border
-	gfx_fill_rect_inset(dpi, x + widget->left + 4, y + widget->top + 15, x + widget->right - 4, y + widget->bottom - 4, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, x + widget->left + 4, y + widget->top + 15, x + widget->right - 4, y + widget->bottom - 4, w->colours[1], INSET_RECT_F_30);
 
 	// Graph
 	x += widget->left + 22;
diff --git a/src/windows/ride.c b/src/windows/ride.c
index e60006ff21..0106118c0c 100644
--- a/src/windows/ride.c
+++ b/src/windows/ride.c
@@ -3650,7 +3650,7 @@ static void window_ride_operating_paint(rct_window *w, rct_drawpixelinfo *dpi)
 		w->x + window_ride_operating_widgets[WIDX_PAGE_BACKGROUND].right - 5,
 		w->y + 104,
 		w->colours[1],
-		0x20
+		INSET_RECT_FLAG_BORDER_INSET
 	);
 
 	// Number of block sections
@@ -3695,7 +3695,7 @@ static void window_ride_locate_mechanic(rct_window *w)
  */
 static void window_ride_maintenance_draw_bar(rct_window *w, rct_drawpixelinfo *dpi, int x, int y, int value, int unk)
 {
-	gfx_fill_rect_inset(dpi, x, y, x + 149, y + 8, w->colours[1], 0x30);
+	gfx_fill_rect_inset(dpi, x, y, x + 149, y + 8, w->colours[1], INSET_RECT_F_30);
 	if (unk & (1u << 31)) {
 		unk &= ~(1u << 31);
 		if (game_is_not_paused() && (gCurrentTicks & 8))
@@ -5276,7 +5276,7 @@ static void window_ride_measurements_paint(rct_window *w, rct_drawpixelinfo *dpi
 
 		x = w->x + 4;
 		y = w->y + window_ride_measurements_widgets[WIDX_SELECT_NEARBY_SCENERY].bottom + 17;
-		gfx_fill_rect_inset(dpi, x, y, w->x + 312, y + 1, w->colours[1], 0x20);
+		gfx_fill_rect_inset(dpi, x, y, w->x + 312, y + 1, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 	} else {
 		ride = get_ride(w->number);
 
@@ -5312,7 +5312,7 @@ static void window_ride_measurements_paint(rct_window *w, rct_drawpixelinfo *dpi
 			y += 20;
 
 			// Horizontal rule
-			gfx_fill_rect_inset(dpi, x, y - 6, x + 303, y - 5, w->colours[1], 0x20);
+			gfx_fill_rect_inset(dpi, x, y - 6, x + 303, y - 5, w->colours[1], INSET_RECT_FLAG_BORDER_INSET);
 
 			if (!(ride->lifecycle_flags & RIDE_LIFECYCLE_NO_RAW_STATS)) {
 				if (ride->type == RIDE_TYPE_MINI_GOLF) {
diff --git a/src/windows/scenery.c b/src/windows/scenery.c
index 1f21253aaf..fc9b87e181 100644
--- a/src/windows/scenery.c
+++ b/src/windows/scenery.c
@@ -1103,16 +1103,16 @@ void window_scenery_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, int scrol
 		{
 			if (w->scenery.selected_scenery_id == currentSceneryGlobalId) {
 				gfx_fill_rect_inset(dpi, left, top, left + SCENERY_BUTTON_WIDTH - 1,
-					top + SCENERY_BUTTON_HEIGHT - 1, w->colours[1], 0x80);
+					top + SCENERY_BUTTON_HEIGHT - 1, w->colours[1], INSET_RECT_FLAG_FILL_MID_LIGHT);
 			}
 		} else {
 			if (tabSelectedSceneryId == currentSceneryGlobalId) {
 				gfx_fill_rect_inset(dpi, left, top, left + SCENERY_BUTTON_WIDTH - 1,
-					top + SCENERY_BUTTON_HEIGHT - 1, w->colours[1], 0xA0);
+					top + SCENERY_BUTTON_HEIGHT - 1, w->colours[1], (INSET_RECT_FLAG_BORDER_INSET | INSET_RECT_FLAG_FILL_MID_LIGHT));
 			}
 			else if (w->scenery.selected_scenery_id == currentSceneryGlobalId) {
 				gfx_fill_rect_inset(dpi, left, top, left + SCENERY_BUTTON_WIDTH - 1,
-					top + SCENERY_BUTTON_HEIGHT - 1, w->colours[1], 0x80);
+					top + SCENERY_BUTTON_HEIGHT - 1, w->colours[1], INSET_RECT_FLAG_FILL_MID_LIGHT);
 			}
 		}
 
diff --git a/src/windows/text_input.c b/src/windows/text_input.c
index 7280eb8b4d..49c94e324d 100644
--- a/src/windows/text_input.c
+++ b/src/windows/text_input.c
@@ -270,7 +270,7 @@ static void window_text_input_paint(rct_window *w, rct_drawpixelinfo *dpi)
 	// +13 for cursor when max length.
 	gfx_wrap_string(wrapped_string, WW - (24 + 13), &no_lines, &font_height);
 
-	gfx_fill_rect_inset(dpi, w->x + 10, y, w->x + WW - 10, y + 10 * (no_lines + 1) + 3, w->colours[1], 0x60);
+	gfx_fill_rect_inset(dpi, w->x + 10, y, w->x + WW - 10, y + 10 * (no_lines + 1) + 3, w->colours[1], INSET_RECT_F_60);
 
 	y += 1;
 
diff --git a/src/windows/themes.c b/src/windows/themes.c
index 6d787f2e17..026f0df566 100644
--- a/src/windows/themes.c
+++ b/src/windows/themes.c
@@ -836,7 +836,7 @@ void window_themes_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, int scroll
 				}
 				gfx_draw_sprite(dpi, image, _button_offset_x + 12 * j, y + _button_offset_y, 0);
 
-				gfx_fill_rect_inset(dpi, _button_offset_x + 12 * j, y + _check_offset_y, _button_offset_x + 12 * j + 9, y + _check_offset_y + 10, w->colours[1], 0xE0);
+				gfx_fill_rect_inset(dpi, _button_offset_x + 12 * j, y + _check_offset_y, _button_offset_x + 12 * j + 9, y + _check_offset_y + 10, w->colours[1], INSET_RECT_F_E0);
 				if (colour & COLOUR_FLAG_TRANSLUCENT) {
 					gCurrentFontSpriteBase = -1;
 					gfx_draw_string(dpi, (char*)CheckBoxMarkString, w->colours[1] & 0x7F, _button_offset_x + 12 * j, y + _check_offset_y);