thanks for all these postings; was thinking of trying but definitely won't now!  I have been doing my own hair forever, and find that the best solution is to stick with the demi-permanent! I have also used 10 volume developer with permanent dye, and it worked fine! gave me colour that stayed! why not just do that?  I also found that for some reason the best colour I've used came from Sally Beauty brand (Ion), but Colorianne (Italian brand) is also amazing.