A friend of mine has a program on his computer that is apparently quite common although I don't have it. It's a normal photo editing program with a "mask" option. This in effect lets you turn a photo into a 2D image with all of the separate colors actually separated and able to be changed independently. So if you want to see what a mocked up bike might look like in different colors, you just make sure that the frame is a different color than the other parts on the bike, then take a pic. Load it into the computer and transport it to photo editor, mask it, and start playing with the colors. He also downloaded a program as an add-on to the original editor that gives you more color options, including metallic colors, and a fade control that allows you to change the shade or darkness/brightness of the same color . So you can try out a metallic green, then tweak it until you get the metallic green you want. However there's no telling how you might go about finding whatever color you choose out here in the real world. Maybe print it off and take the sheet to the local auto paint shop. You can also mask the other parts, so long as there is a definite separation between that part and the others. However we had slight difficulty when parts of very close color, especially chrome ,overlap. One solution is to tweak the contrasts so that you see some more separation
