I just tried this product for the first time today and my hair looks awesome. I have dark brown hair that I have colored at the salon every 4 weeks - - the "skunk line" of grey shows up right at the 3 week mark. My stylist recommended this product to me for in between touchups and provided it stays in after washing, I am all set! I did leave the product in for 35 minutes and I was careful to only touch up the roots and not the rest of my hair. Make sure you use an old towel; I was very careful to rinse everything out and still ended up with brown dye on my good towel. I also washed my hair right away after rinsing out the product....Can't wait to go back to CVS and get another 3 boxes!