One quirk of doing things the way I have above, is that it allows us to basically take two distinct images and then merge them together into the final result. I start with the image of an egg, and an image of a rainbow screen. I then basically take the rainbow colors from it's screen, wherever the egg would appear on its screen, and then copy those onto the display screen...
Using this method, I could also, conceivably, take egg-shaped portions of screens from a movie and then put them onto the display, only showing the "egg portion" out of the movie screen. Or I could take egg-shaped images from moving flames or raindrops falling, and then display them to the screen, as I'm not so much coloring an egg, as just taking the egg-shape color information from a different image.
Movie Easter Eggs -- how great is that concept?!!