Eh, if you are asking me what my favorite colors are, I can answer that.
Asking what is a good color, is too vague to answer...good for what is what I think when I read it.
Anyways, here are my thoughts on colors for the a car like the Supra (I also posted this before in a 'parellel universe'. heheh
I love vibrant royal blue. It is one of the colors I painted my bike with in my three color paint job. Check this blue out:
I also like the other two colors in that I chose for that job: GM's Torch Red and pure unmixed white.
My first choice for a sports car would be that vibrant royal blue because I already had the Torch Red.
If not that vibrant blue, I would go with GM's Torch Red again. If put on a white base/primer/sealer it would be as vibrant and bright as it should be.
Red is definitely one of my favorite colors on a car. It is not as dark as a real blue, but not as light as yellow. I am so glad my car was red.
Another nice color is white.
This is a very classy color in my opinion, but is also sporty as well.
Out of the 7 helmets I have had, all of them are either white or have white as a background. Two out of two bikes I have ever owned also had white for the main color. Unmixed white is my favorite of all whites and the easiest to fix.
I also like HOK's Orion Silver. Silver is to me is supposed to look as much like silver (the metal) as possible. The more metallic it looks, the better.
Yellow is cool if done on a car with exterior modifications. On a car that is not all that modded with tasteful exterior mods, it does not have the same effect. On a car that looks badass, it makes the car look sporty. If on a car that is not so great or sporty, it makes the car look weak. You can see this when yellow is not on sports cars sometimes such as little econo cars. Yellow has two meaning for me: sporty & weak. Matching it to the right car is vital. Canary yellow is the only yellow that I would ever consider! Mello's car--the one in his avatar--is that color. On his car, it looks great. On a wingless stock looking Supra, I don't think I would like it at all.
For the easiest color to fix, I would go with straight black (unmixed black).
That color will show off the shine if you have a nice clearcoat finish as well.
The bodywork has to be done right as poor bodywork will show more with black than with very light colors--but then perfect body work should always be performed anyways!
As far as painting, that is the easiest color to blend/fix/spray.
Black is something I can see anytime I close my eyes, so in that sense, it is not so special. Black can hide body lines too. It has an attitude but somehow does not tantalize me too much. For warmer and sunny climates, it would make your car lots of fun to get into also (being sarcastic of course since black would absorb heat).
Pearls are not even worth considering. For their effect, it is not worth having to fix them or even paint them.
Real candy colors are for more advanced painters. Fixing them is for even more advanced painters. They would look awesome but you will most likely kick your self in the ass if you even need to fix something painted with a candy.
Some of the above is opinions, but some are facts.