What he said.
I have an older version for Photoshop when I use it so not sure how it applies to what you're on. I use the pen tool to trace an area, turn the tracing into a selection using the icon at the bottom of the paths palette. Then you can use the image adjust > Hue/Saturation tool to get a basic color to work with. From there you can "paint" over the base color in a layer on top to get high contrast different shades and hues.
To match a color of another car, bring it in on another layer and simply use the eye dropper color select tool on the color you like and it'll put that color in the palette. Then paint away. When you're done grabbing colors just dump that example photo layer from the illustration.
Hope this all makes sense.
PS those are great football photos XcYZ, nice work!