Depth is easy to add. The trouble is that lifted hair has nothing underneath for it to sit on.

Every colour client is on a slow slide towards darker, flatter ends, and it is caused by us.

The appointment most salons run most weeks, and the one most likely to be done on autopilot.

The first appointment with a new colour client decides the next two years of them.

Nine variants with no depth at all, and they decide whether the other 151 land where you intended.

Twenty shades that lift and deposit in one step, using a ratio nothing else in the range uses.

Fifty-one variants in the warm families, and the doubled-digit convention that turns the intensity up.

Ash does not add a colour so much as remove one, and on the wrong head it removes too much.