How well do you know your gun? I started with white but picked up some black ones cause I was curiouse.
I found a 80/20 split of black to white is actually really good. You get about 5 -10 blacks than a white or two as a tracer. Enemy has no idea where you are, it forces you to use your sights as well so it adds an edge of realisim to the game.
Adjust your hop up THAN load black BB's.... Adjusting hop up with black BB's is next to impossible