Balayage is not a colour, it is a placement. Two clients can ask for the same soft root and leave with completely different hair, because the colour is painted where each head grows rather than measured out in foils.
We start by reading the hair in daylight: how much warmth is already there, where it has been lifted before, and how porous the mid-lengths have become. That decides how strong the lightener is and how long it sits. Rushing that step is how balayage ends up brassy or patchy.
Then we choose the placement. A section at the front takes light higher, the crown stays closer to your natural depth, and the tips round the face are painted to blend. It is slower than foils and that is the point: the grow-out should look intentional three months later.
Finally, toner. Gloss and toner are what turn a lift into a result, and they are mixed for your skin tone — the same level of lift looks warm on one client and flat on another.