protected void paintOverComponent(Graphics2D g2d, GGlassPane glassPane) {

			Rectangle bounds = getComponentBounds(glassPane);

			float alpha = .7F; // arbitrary; allow some of the background to be visible
			AlphaComposite alphaComposite = AlphaComposite
					.getInstance(AlphaComposite.SrcOver.getRule(), alpha);
			Composite originalComposite = g2d.getComposite();
			Color originalColor = g2d.getColor();
			g2d.setComposite(alphaComposite);
			g2d.setColor(component.getBackground());

			g2d.fillRect(bounds.x, bounds.y, bounds.width, bounds.height);

			g2d.setComposite(originalComposite);
			g2d.setColor(originalColor);
		}
Hides any message being displayed.  This can be called even if the message has been hidden.
Ghidra/Framework/Docking/src/main/java/docking/util/GGlassPaneMessage.java