+22 Hair Color Timing Chart Ideas. The standard measurement for hair colour levels is on a scale of one to 10, with level one being the darkest (i.e. For healthy hair, you should not lift more than four levels of color in a single session.
It’s your ultimate color guide. Explanation of the numbering system in hair color levels. Mixing ratios can be tricky to get right, so a hair colors chart or hair color scale takes the guesswork out of it.
