Review on Just For Men Shampoo-In Color (Formerly Original Formula), Dark Brown, Pack of 3 - Perfect Gray Hair Coloring for Men! by Tyler Turner

Light medium brown is almost my (original) hair color so it looks very natural. but sometimes it doesn't mix well enough because when they're both in the big bottle there just isn't room in the bottle to mix them properly. So I put them both in a separate tiny plastic cup and mix them together with a cotton swab - and it seems to work a lot better. Then I fill it back into the spray/application bottle. To keep the color permanent you will probably need to do this every 3 weeks and you cannot store the material once you have mixed it. In addition, my sideburns are immune to this substance, so they remain partly gray, which is fine with me. It will take several times to debug the process so you can do it quickly and cover all the hair completely. I missed a few spots at the back the first time, but now I just use way more than seems necessary and see if my hair is all wet. Also, it's a bit messy and will mess up the sink, so ditch an old shirt or something first. In any case, I'm happy with it.