Choice of primer color should not be an "all or nothing" affair. For figures that use a lot of metallics, I use black. For figures using lots of lighter colors (perhaps white robes) or NMM, I use white. All of my bases are primed black before drybrushing. And for most of my figures, I will prime different parts of the model with different colors (for example, I will mask off faces on black primed models, and prime the face white - flesh is hard to paint over black). I use spray cans (GW black primer is excellent, but I dislike their white), airbrush priming (for nice smooth consistency, I only do batches of figures with the airbrush due to setup time) and brush-on priming (usually Vallejo White GameColor primer).