Actually, it probably will hurt the resale value. There are codes that tell wiat the original color was and so that can easily be detected. Also, most repaints by most body shops are not undetectable. There is usually some minor flaws and imperfections that will show up.
Also, it is very expensive to repaint a vehicle a different color since there are so many more serfaces that must be painted and even then they don't paint behind interior panesl, so if someone removes a door panel, the old yellow paint will be there, etc.
A complete repaint to black could easily cost you $4000 or more. Not to mention the loss in resale value....The question will alwasy be, "Why was it repainted?" Many people will think it was severely wrecked and perhaps should have been junked?
If you don't like the yellow, you are far better off selling it and buy a black one.
The only acception might be if you had a custom, show quality paint job done on it, but that is really expensive $10k and up and if you are going to spend that kind of money, you should dismantal the vehicle, have all the panels straightened and aligned to perfection and the vehicle should be stripped down to the paintable body parts so everything is painted.
...Richard