The pigments that my wife ordered arrived today, and after seeing your project, it inspired me for a project of mine...
Here is a link to their tips on how to use their products. Maybe it can help you with yours.
http://www.luminarteinc.com/primary-...ts-how-to.html
Their pigments are a lot smaller, but they mix them with the clear to apply them. I don't know if this method can be used with bigger pearls though.
Gilles