Natural Colourant options in soap

Many people are trying very hard to stay away from synthetic dyes and colourants these days. So what are the alternatives available to a soapmaker? Below is a list of some natural colourant ideas:

Yellow - Annatto, saffron, Turmeric, Carthamin, Calendula petals (whole or ground)
Green - chlorophyll, Spirulina
Brown - the cocoa bean (pods, shells, stems), cocoa powder, fermented tea
Red - Paprika (may be irritating), Red Rooibos Tea, Carmine
Purple - Alkanet Root (for CP), Ratanjot (can sometimes be more red), Beet Root Powder
Blue- Indigo Root

To name a few.

The biggest draw back to using natural colours is that you won't get a vibrant lemon yellow or a bright lime green using natural colourants. Plus they generally stain when used in large quantities.