Hi everyone! I found this old piece of paper with a hair dye formulation that I got at Aveda once. I'm not a professional, but at this point, I've been trying to experiment at home with dyes from Sally's because I don't have much money to spend for salon color. But I'm just curious, if I ever decide to go back to Aveda, what does the "Lt. Y/O" part of the formula mean?
Retouch formula:
40g 20 vol
40g 7N
2g Lt. Y/O
30 min. - start in front