Wella COLOR CHARM, HAIR COLOR Creme Developer, Hair Color,Volume [40] 32 oz - (Pack of 2)

I use this with the wella powder bleach before putting in new colors. I have dark brown hair, so one application won't completely bleach my hair, but if I use the 40 volume, it'll go to green, and then a day or a week later, it'll go even lighter, though as you can see, once I have already had color in there, the blue and purple colors will still not completely lighten. They're pretty much impossible to strip. But obviously, bleach is harsh on your hair, and 40 volume is strong, but wella seems to damage it a lot less. Make sure you condition the heck out of your hair before and after. In the first picture, you can see my hair is brown at the roots, then it goes to a dark yellow (that's new brown growth that I've bleached one time), then a greenish color (that's where I had the blues and purples that have now been bleached). In the second picture, you can see where it's faded much more, and I won't bleach it more from this point. This is light enough for the colors to come out bright.