Do you mean the colourb4 stuff you can buy in Boots? I dyed my hair bright red for years and ended up using this. It was great and stripped 90% of the red out (I was left with light coppery hair) and then I used a semi-permanent light brown straight away which did take slightly darker, which was expected, and had a very slight hint of red to it when the light caught it. My hair didn't dry out at all and was in really good condition afterwards. Look at reviews on the Boots website as people have posted lots of good tips.