Bill makes a good point. Light pearls (alabaster, silver, etc) in dark paint (dark green, black, dark blue) will have a huge effect. When you put pearls of the same color (green in green), the effect is to make it sort of silvery, but it's a muted effect. Putting green pearls in say, gold, is an interesting effect as is the reverse.
Point is, there are all kinds of things you can do to get all kinds of effects. Just sort of depends on what you're going for. The Cobra I refinished for VSC this year had white, red, blue and yellow/gold trim. I shot some clear with alabaster pearl in it over the top. Just one medium coat. The effect was to turn the whole plane sort of silvery white in the sun. When you looked at it one way, the colors really stood out. Another way and it sort of looked silvery white. It was an interesting effect.