Every hair colour is described by two things. The level is how light or dark it is, from 1 (black) to 10 (the palest blonde). The tone is the colour you see in it: ash is cool, gold and copper are warm, violet cancels yellow.
The shade studio on our home page works the same way, and it colours the hair the way hair is actually coloured — by how much of two pigments, eumelanin and pheomelanin, sit in the fibre. Lightening removes eumelanin first, which is why lifted hair turns warm before it turns pale.
