Colour B4

I went to the store today to find some decolorization for my hair. .D In order to get my hair green again I think I need to do one of those.

I found a new thing I have never seen before:

Apparently it is gentler on the hair than other brands, and after some googling it seems to be true, I find only good reviews of it.

Someone here who has tried it? 

I think I will let my hair rest for 2 weeks and get some black out of it the natural way , and then I'm gonna try this.