Henna is a naturally derived pigment that coats the cuticle of your hair, and if your intent is to keep on doing henna as an alternative to conventional hair color, then a Brazilian Keratin Treatment should give great results, since up top 80% of the curl and all the frizz can be removed, and a BKT is not a chemical service, but only a treatment, so the hair quality is improved, not compromised. BKT is also a good choice for Grey or White hair, since when the hair ceased to produce melanin pigment and goes first grey.. some granular pigment still left.. and then White.. no pigment... not only does the color change, but the Texture changes as well, and the de-pigmented hair is very coarse and wiry, since the cuticle is now compact. Whoever does the BKT should be certified by the company and well experienced with the product, since grey hair must be addressed keeping in mind that compact cuticle. The Certifications are usually posted in the salon, and show the name and license of the stylist, and also say when that stylist was certified to use that brand.