private Color getColor(Address address) {
		Integer value = colorMap.getValue(address);
		if (value == null) {
			return null;
		}
		Color c = colorCache.get(value);
		if (c == null) {
			c = ColorUtils.getColor(value);
			colorCache.put(value, c);
		}
		return c;
	}
Default {@link BackgroundColorModel} for the ListingPanel where the color returned
for an index is based on that corresponding address having a color set in the
program's database. (You can "paint" colors over address ranges).
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/listingpanel/PropertyBasedBackgroundColorModel.java