Bruce: There was a 550 replica here in New England a long while back that was Ford "Dark Moss Green" for 1967-1968. Same green metallic as McQueen's Mustang in Bullitt. Looked awesome to everyone who saw it, but that is a dark green.
I can't envision a 550 in Charger green (which looks a lot like Kawasaki motorcycle green).....I simply can't see it in my mind, but try this: Get a small die-cast model of a 550 and a few cans of spray paint in the colors you like. Spray it and take photos of it with your "smaht fone". You could even be creative with backgrounds to make it look more realistic. That's about the easiest/cheapest way I can think of this side of Photoshop to play with different colors on your car.