Rita Hazan Weekly Remedy Treatment (£34) is an impressive masking treatment for colour-treated hair. The quick, two-step treatment can be used in the shower and rinsed off immediately, which means no hanging around for it to soak in. It's definitely one of the most expensive masks on the market, but I can confirm the promise of immediate results (think: less frizz, smother strands, brighter colour in one wash) is true. I was also surprised how long these small tubes lasted — a little goes a long way.