paint design programs???? help

[racer_99]

This is off topic from my camaro but you guys are always so much help thought I would ask. I have a car that I am getting painted and I can't wrap my mind around how it will look before I pick paint. So I am in need of a download or program where i can put different designs and maybe two tone it and make it look good so I can see what it will look like with different colors before I mess up and put colors on it I don't like. I was hoping there was a program i could download a pic and change colors and designs thanks