Question: when dying hair how much developer?
Answer: The mixing ratio is 1:2. 1 part color with 2 parts developer (1 oz. of hair color combined with 2 oz. of developer, for a total forumula mixture of 3 oz.).
Pour 2 oz. of developer into a tint bowl or an applicator bottle.
Add 1 oz. color.
Gently shake/mix and apply color.