public void setBackgroundColorModel(ListingBackgroundColorModel colorModel) {
		if (colorModel == null) {
			fieldPanel.setBackgroundColorModel(propertyBasedColorModel);
			layeredColorModel = null;
		}
		else {
			colorModel.modelDataChanged(this);
			layeredColorModel = new LayeredColorModel(colorModel, propertyBasedColorModel);
			fieldPanel.setBackgroundColorModel(layeredColorModel);
		}
	}
Sets the externally supplied {@link ListingBackgroundColorModel} to be blended with its own
{@link PropertyBasedBackgroundColorModel}.

@param colorModel the {@link ListingBackgroundColorModel} to use in conjunction with the
           built-in {@link PropertyBasedBackgroundColorModel}
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/listingpanel/ListingPanel.java