Just 5 is the gentle permanent hair colour because it works fast, in just 5 minutes, contains no damaging ammonia, and protects your hair with replenishing conditioners as you colour. Then it fortifies hair with a rich after-conditioner for brighter shine and to provide superior grey coverage. It is so gentle, so can even colour the day after you relax. Results are permanent. Superior grey coverage: Your natural hair colour is actually a blend of many close shades. That's why this hair colorant blends shades of your own colour into the grey so invisibly, even you can't tell which hair used to be grey. Won't wash out, won't fade out no matter how often you shampoo. It lasts up to 6 weeks, or until your grey grows back. Made in the USA.