Illumina uses Wella’s slash numbering: 7/43 = level 7, primary reflect 4 (red) and secondary 3 (gold).
- Level (before the slash): the depth, from brown to lightest blonde.
- First digit after the slash: the reflect in charge.
- Second digit: the supporting tone, always in a smaller proportion.
The reflect key: 0 natural, 1 ash, 2 matt, 3 gold, 4 red, 5 mahogany, 6 violet, 7 brown, 8 pearl, 9 cendre. A code ending in a slash with no digits, like 7/, is the pure natural of that level.
An 8/13 means the same in Illumina, in Koleston and in Color Touch: level 8, ash with gold. The chemistry changes, the reading does not.