public static Color withAlpha(Color c, int alpha) {
		return new Color(c.getRed(), c.getGreen(), c.getBlue(), alpha);
	}
Returns a new color that is comprised of the given color's rgb value and the given alpha
value.
@param c the color
@param alpha the alpha
@return the new color
Ghidra/Framework/Gui/src/main/java/ghidra/util/ColorUtils.java