Rita Hazan True Color Ultimate Shine Gloss (£21) is one of the easiest treatments to use in my opinion. The foam formula makes it a doddle to coat every strand with zero mess, and even better, you can do it quickly in the shower without waiting around long for the formula to get to work. Simply shampoo your hair, apply the Ultimate Shine Gloss, and rinse immediately, or wait up to three minutes for a more vivid colour boost, and then condition as normal. The gloss comes in five shades: clear, blonde, brown, red, and breaking brass to help refresh colour and add intense shine.