First off welcome to the Do-It forums.
Second, do not use any water based paints [many of Createx's paints] or water based / water borne colorants to the plastic either raw or re-melted. Big time dangerous and sever burn hazard. Water anything and the hot plastic are not good company. As a rule, any colorant shown on any of the mold/plastics access sites can be used with any brand of raw plastic. There may be one or two brans of plastic that conflict but they are generally labeled as such.
You can use the ProTec powder paint in the powder form to color your raw plastic but it takes some getting accustomed to mixing as the colors may not come out as you expect. I've also heard of people using the powder form of Rit fabric dye to color the raw plastic so I'm sure that other powdered forms of fabric dye would achieve the same.
Again, welcome aboard.