I'll second PaPitt.
I've had great luck with factory colors blending. What becomes more difficult are repaints that aren't exact to begin with and then having to try and figure out which direction to go with laying it down and the color and maybe that's because I'm not a painter by trade.
Is your truck a base/clear or an older single stage? If you wax it does color come off onto the rag?
Color does not come off on the rag... I assume base/clear...