Color, Color, Color! - Alternative ways to color resin...

I've seen some conflicting information on what you can and cannot use to color resin. Now, as far as I know you can use practically anything sort of dry pigment - such as (my favorite) Pearl Ex powders, tempura powder, pastels, micro glitter...you get the idea...Now for liquids, I've read some sources that say you can ONLY use dyes and pigments specially formulated to work with resin. But I've