Bug 163345 [Field Assist] - API - Deprecate DecoratedField and related classes
If ControlDecoration is adopted in replacement of DecoratedField by all existing SDK clients, then we should deprecate DecoratedField.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/FieldAssistColors.java
Object storedColor = requiredFieldColorMap.get(control.getBackground());
		if (storedColor != null) {
			return (Color) storedColor;
		}
		
		
		Color dest = control.getBackground();
		Color src = display.getSystemColor(SWT.COLOR_YELLOW);
		int destRed = dest.getRed();
		int destGreen = dest.getGreen();
		int destBlue = dest.getBlue();
		
		int alpha = (int) (0xFF * 0.15f);
		
		destRed += (src.getRed() - destRed) * alpha / 0xFF;
		destGreen += (src.getGreen() - destGreen) * alpha / 0xFF;
		destBlue += (src.getBlue() - destBlue) * alpha / 0xFF;
		
		Color color = new Color(display, destRed, destGreen, destBlue);
		
		requiredFieldColorMap.put(dest, color);
		
		
		if (!displays.containsValue(display)) {
			display.disposeExec(new Runnable() {
				public void run() {
					disposeColors(display);
				}
			});
		}