"Whether we use one or not, and the kind of toner we use, all depends on the colour we’re trying to achieve and it’s usually at the very end of the process when a trained eye can see what is needed that we’d add it in," Luci said. Essentially, if hair dye is foundation , a toner is bronzer : it doesn’t change the shade you’ve applied, it merely shifts it, adding warmth and dimension. "Toner is the icing on the cake," added Luci. "It only takes a couple of minutes to apply at the backwash, either through the whole head or just in the sections we want to change slightly. It really is a very versatile product and doesn't change the structure of the hair in any way."So far, so good. If you’re a new blonde , it’s very possible you’ve had toner used on your hair in the salon – as Luci noted, it takes mere moments and doesn’t add much faff, so your colourist may have already made that correction for you. What’s more, it will gradually fade out of the hair as the colour settles, rather than 'washing off' all at once, so you might not notice the shift at home. The catch? When I asked Luci if all blondes , or indeed, all coloured hair types should be using a toner at home, the answer was a resounding no. "Toner really isn’t for everyone. It’s only really needed for softening hair colour, and it’s part of a whole colouring process. Hopefully, you can achieve the hair goal without toning." She added: "We use toner mainly after scalp bleaching, or during something like ombré or balayage where you have those textured tones."If you’re a seasoned home hair colourist, you might know exactly what you’re doing and exactly when to do it. In that case, more power to you! Please drop a tutorial. But if you’re happy with your salon results and you’re thinking of trying toner just because you feel you should, that’s not the right reason to do it. Speaking as a bottle blonde of some six or seven years, I know that it’s hard to keep fresh, but it’s all too easy to do more harm than good at home.