Depending on the scent, I have used rose clay, cocoa powder, and many of the different oxides. They don't fade at all. And I haven't had them get gross when mixed with essential oils either. Another one I do is a spiced vanilla, which I put nutmeg in the vanilla salts. It turns it a slight brown. I gave up on food coloring, it didn't last at all. Oh, and my salts are just regular rock salt, so DSS may be different.