if your wheels are black...I would think you need the most cans in white...then maybe 2 pearlizers and one or 2 glossifiers. Since your wheels are black, I would do one can of color per wheel. You might get away with 3 cans of white for all 4 wheels but thicker is better and white over black is the hardest combo. use 4 cans of white... 2 pearl/1 gloss. The gloss is just a protectant. But the pearl is really just a glossifier with pearl in it...it is not opaque at all and comes out clear just like the metalizers/glossifier. You may not want to do gloss though. It does change the color, hue and general look of any color. I like to use it on dark colors but It does jive well with pearl white from my experience.