Lots of ifs involved here. If you buy all the paint in one batch at the same time. If you prep the base exactly the same each time. If your application is the same each time you spray. If it's a straight color instead of a metallic. If you blend all of the cans as you mix.
If after you paint every panel and reassemble them you scuff the whole truck and lay down a couple of good coats on the entire truck, then you might have it all one shade.
All that said, I have seen professional painters that have painted cars/trucks in stages and had them come out OK.
Denny Graham
Sandwich, IL
