There is a specific type of pearl that is commonly used for the effect you're talking about.....they're called "ghost" pearls. In their container they look like a white powder--if you get a little on your finger and look at it in the sunlight you can see the actual color. The easiest way to use them is to add the powder sparingly to your clear--best to start with a small amount and add more as you like to get the effect you want. In the finished work they are virtually invisible until light hits them at the right angle. Ghost pearls come in a number of colors.....gold, blue, green, red, violet, orange, silver. Another basic use for ghost pearls is: start off with a white pearl base coat, then add whatever color ghost pearl to your clear and spray a couple of EVEN coats overall.....then a few coats of straight clear with no pearl in it. In the sun you will still have a white pearl finish but you will see the color of your ghost pearl appear and disappear as you walk around and change your viewing angle.
Then there are pearls called "Ice Pearls" ( by House of Kolor) or "Ice Crystal Pearls" ( from Kustom Shop, or TCP Global). These are actually tiny bits of glass coated with various colors....like ghost pearls, they are virtually invisible until light hits them--then they sparkle like crazy, almost like a metalflake!
1.Pearl (or mica) powders are made and sold by a number of companies, one of the more well-known being House of Kolor--one place you can find HOK pearls is
www.coastairbrush.com Another place that makes and sells their own line is
www.kustomshop.com Kustom Shop Ice Crystal pearls seem to my eyes to be the same as HOK Ice pearls but for a much lower price. Even better prices can be found at cosmetic sources (where they are known as "mica" powders) such as
www.coastalscents.com or
www.madminerals.org Cosmetic sources also sell small samples for a couple of dollars so you can experiment without having to buy a whole ounce of powder.
2. the two main basic methods for using these pearl powders is to 1. add the directly to your paint (any paint, urethane, water-based, waterborne, whatever) which works best if your paint is transparent or translucent rather than opaque...or 2. add the pearl powder to your clear base (for water-based or waterborne) or to topcoat clear (for urethanes) and then spray on top of your basecoat color. Another neat effect I've found is to add the pearl powder to your clear base, but don't reduce or thin for spraying.....instead you can use a piece of crumpled saran wrap or a sponge to dab it on your surface for a marbleized look. Whatever method you use....they all need to be clear coated with straight clear, no pearl added, to protect your final finish. Depending on the effect you're after, it generally takes less pearl powder to show well or cover black or dark base coats than it does to show or cover white or light colored base coats.