Here are my favorite micas and oxides which I highly suggest. I LOVE Nurture Soap because their values are in line with Green Girl Basics. All of their colorants are ethically & sustainably sourced, vegan, and cruelty-free. Their colorants do not fade or bleed and are true to their descriptions.
I personally use these at a rate of 1/8-1/2 tsp per pound of soap making oils. I have been suggesting Nurture Soap's colorants for quite a while and have recently become an affiliate with this company. I now earn a small commission when you make a purchase through my website. Prices listed are for an 4 oz jar as this is a good value and will keep you from having to order often.