private void getBothStringHighlights(String text, int cursorTextOffset,
			ArrayList<Highlight> highlightList, VTMarkupItem markupItem) {
		StringStringable sourceValue = (StringStringable) markupItem.getSourceValue();
		StringStringable destinationValue =
			(StringStringable) markupItem.getCurrentDestinationValue();

		String sourceComment = (sourceValue != null) ? sourceValue.getString() : null;
		String destinationComment =
			(destinationValue != null) ? destinationValue.getString() : null;

		if (sourceComment != null && sourceComment.length() > 0) {
			Highlight sourceHighlight =
				getHighlight(text, cursorTextOffset, markupItem, sourceComment);
			if (sourceHighlight != null) {
				highlightList.add(sourceHighlight);
			}
		}
		if (destinationComment != null && destinationComment.length() > 0) {
			Highlight destinationHighlight =
				getHighlight(text, cursorTextOffset, markupItem, destinationComment);
			if (destinationHighlight != null) {
				highlightList.add(destinationHighlight);
			}
		}
	}
Creates a darker shade of the color passed-in, based on the given amount.

algorithm: 1) grab individual rgb elements
           2) multiply each by a factor.
           
           ie: int newRed = (int)(oldRed * 0.85);

@param color the color to shade
@param amount number between 0..1 (the smaller the number, the darker the shade)
@return the new color
Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/duallisting/VTDualListingHighlightProvider.java