This day and age there are many Companies who offer that type of coloring for their epoxies. Some use there standard epoxy and sell you pigments. Other Companies sell it pre-pigmented and then there are a few that reformulate there epoxy to have less surface tension and longer work-ability and sell you designer pigments apart.
These systems can be applied in numerous ways to create different effects. You can go from mild to wild. Between color and application method, there are boundless looks you can achieve.
MILD
SUBTLE
WILD
Molten
2 COLOR MOLTEN
STORM
2 COLOR
3 COLOR
6 COLOR
There are infinite possibilities