What are the best materials to use for colouring Plaster of Paris?

Question: What are the best materials to use for colouring Plaster of Paris!?

I want the actual plaster to be coloured, not just the surface, but I want it to still be as strong!.Www@QuestionHome@Com

Best Answer - Chosen by Asker:

powder pigmentWww@QuestionHome@Com

I don't know if its the best, but acrylic paint worked for some people I know!. You don't get very strong colors though, they are all in the pastel range!.Www@QuestionHome@Com