From Artistic Adornment:
Christine Shahin has written THE book on natural hair coloring using henna, indigo, cassia, and amla. She has taken all of the information natural hair coloring out there, added years of hands-on experience as a professional hair stylist, and tied it all together with beautiful writing and a stunning collaboration with a professional photographer and many, many models with all different hair types.
Every single person who wants to do natural henna (etc) hair dye should get this book. Even for people with years of experience doing henna on their own hair or a few select clients will get so much out of this book, as the recipe section is very comprehensive. This book is priceless, and the most succinct/complete resource on the topic to date.
From the publisher:
Commercial hair dyes contain thousands of different chemicals, some of which are reported to be carcinogenic — but you don’t have to choose between gorgeous color and good health. Natural hair care expert Christine Shahin shows you how to use nontoxic plant pigments — henna, indigo, amla, and cassia — to color your hair naturally, whatever your hair type or ethnicity, with beautiful results! These pigments are readily available at natural food stores and online, and they’re simple, safe, easy to use, and cost-effective. With clearly written instructions and step-by-step photography, Shahin shows you exactly how to apply these pigments, alone or in combinations, to achieve a full range of shades of brown, black, and red. She also includes instructions for transitioning from chemical dyes to natural ones and for using chemical and natural dyes together.
This is a PRINTED, physical book, and will be shipped to you.
(Since we have so many ebooks and that's the norm here, we find it worth mentioning one more time.)