I can't have "fantasy" colored hair, really, because of my job, but I insist on trying to push the envelope a little...I came across this stuff on Pinterest and ordered the daily conditioner to give it a try. I'm in Vegas, so I received it within 2 days, which is awesome. For the past two weeks, I've been alternating the extreme red and extreme purple daily conditioners on my super dark, almost black/smidge of violet-y hair. I do have a few bleached pieces that I was expecting the color to really show in my bangs, and I was not disappointed. There's a beautiful, rich, burgundy/purple-y color deposit on my bleached pieces and my very dark hair has a gorgeous burgundy tint in it, even when it's not in the sun. I wasn't sure if this would show at all on my super dark hair, but it complements the color I have in it so beautifully. I just ordered the Go-Deep in extreme red and purple to see what those do and how they enhance my subdued color. Also, I currently have the Brazilian Blow-Out treatment in my hair, and Overtone works with it just fine. What an awesome idea and product. I heart Overtone.