They do 10,12 and 14% in brown and gold tones. I use the brown range as the gold is supposed to be too golden . I only really use 12% on clients. I don't like the fade off on 14%. Why don't you ask them for a sample of 12%. It's a lovely natural colour. It's all trial and error with tan colours. As for the booster drops, I used to put a few drops in per 50ml so if I had 100 ml in the cup I'd add about 5-10. It's not a drastic difference so don't worry. X