I found this today and thought of your post. Don't know if it works personally...


//www.curezone.org/blogs/m.asp?f=235&i=5

http://www.hennaforhair.com


AWESOME website...discusses henna, indigo, henna + indigo in combination, curly hair, gray hair...just a huge resource for using henna and indigo. Biggest secret: henna sold on a shelf, in a box, may not be pure henna, and there's no good way to enforce truthful labeling. The only way to be sure is to order body-art-quality henna from a reputable importer. Usually, it's the non-henna components that screw things up.

You might be able to handle having a perm and henna, if you're willing to get pure henna and experiment. One trick they recommend on that website is: order a tiny sample of henna from them, get some of your hair from your hairbrush, make your henna mix, then dye it, and see what happens.

Also, consider not having a perm! Perms are pretty terrible for you, in terms of the chemicals.