Welcome to the forum and thanks for those photoshop examples! They look great! I generally like bright or dark colors, such as red, darker blues (not navy) etc. However, all those colors look good on the Solstice. I guess a good design will do that for you!
I cannot wait to see what colors will be available on the production car!
Anyone worried about the warranty on their paint, cause you could have what ever color Solstice you would like! For me I'm thinking maybe a metallic deep blue with green pearl coat ^^. But I'm mostly crazy anyway, mostly.
Changing colors in Photoshop is pretty easy. The method I've used is:
1) Draw a path around the painted surfaces of the car. remember to exclude the tires, trim, glass, interior, etc.
2) Turn that path into a selection.
3) Copy the selected area.
4) Paste the selection into one or more new layers. This way you can play with opacities and try multiple colors easily.
5) On the new layer, with the path still selected, go to "image" then "adjust" then "Color Balance"
6) just move the sliders around and you will change the color of the painted surfaces of the car with out affecting the rest of the car.
This is just the basics, you can get more indepth with it if you want. Of course I left out instructions on basic things like making a path, and creating layers, but for that type of instruction I would suggest you go and get one of dozens of self help books out there. Photoshop is the greatest program ever IMHO. The best part is, as you're learning, you can always go back. If you try something and it's totally wrong, just go back! It's easy to learn yourself.