So glad I found this thread. I've been using NI for several years now, and have been reasonably happy with it. Usually my color starts to fade about 4 weeks after application. I leave it on for 25 minutes, but after reading what Curl goddess wrote, I'll try for longer--now that I know it won't damage my hair to do so.
I have medium-dark ash brown hair, and I like to use a light brown shade (11G Amber Shimmer) that's about 3-4 shades lighter than my own hair because it makes my grays look like highlights, and less noticeable as the color starts to fade, which is nice for the summer. Usually I go just one shade lighter in the winter.
Ditto what others have said about the condish--I love it. Anyone know if you can buy it on its own?
2b/F/ii canopy/front, with a bit of 2c/M-C/ii behind the ears and at the nape. Low elasticity, mixed porosity.
Co-wash/condition: GTTT, Suave Naturals Tropical Coconut, GF Triple Nutrition Fortifying Cream
LI: KCKT, Suave Naturals Tropical Coconut
Style: KCCC, FSG, Giovanni LA Natural Styling Gel