Take a photo of your truck. Convert it to black and white in a photo editor. Get out some colored pens and start coloring. When you have all the sheets in front of you, pick out the color that speaks most to you. Or your wife.
If that sounds like too much work, Visit the internet and do a search for a truck in the color you think you might like. Keep the search simple like "AD truck red." When you find a picture, print it and take it to your painter of choice and say "make this."
