I have a bunch of colors, though not as many as some users on the site, but even with all the variety and options the colors I make the most are: watermelon varieties, green pumpkins, black and various browns. Flake wise I use black, red, purple and green the most but also have blue, silver, gold, copper, holos among many others. Since you're first starting out try and keep it simple and recreate the colors you use the most and go from there.