I currently use Organic Color Systems.  I tried Inoa twice now and both times it seemed to leave my clients hair damaged and looking fried.  Also, Inoa contains PPD's which are highly carcinogenic and I cannot take risks with my client's health.  Their are other ammonia-free brands on the market.  My advice - if you live in the US or Canada, go with a brand that is manufactured in Europe and especially the U.K. where they have much more strict controls on ingredients of hair color.  OCS is the only government certified organic professional permanent hair color available as of now.