Don't mix developer with a dye unless it is instructed on the dye's box! It will only work properly for a mixture it is meant to be in. If you mix it with a semi-permanent dye you're just causing unnecessary damage to your hair.

The simpler answer you’ll hear from most people is that hair developer doesn’t lighten your hair by itself as it’s just a “vehicle” for hair dyes and bleach into the hair. And while that’s technically true, the simple act of opening your hair?

Use volume 10 developer to lift your color a single level. Volume 10 is the weakest developer level, as it contains only 3% hydrogen peroxide. Volume 10 is a good option if you are going just a bit darker than your current hair color and you do not need t