If you mix 1/4 medium ash brown into the shade though, you will neutralize any red tone that would have otherwise shown through, but there won't be enough ash brown added to make your hair look that color. ... If your new color is only slightly darker than you started, you may need to add more ash to counteract the red.

Will medium brown cover red hair?

If you want to color your natural or dyed red hair brown, you should always choose a brunette tone which is at least one level darker than your current color. In other words: if you have cherry-red hair, you will not be able to achieve much with a medium-brown color. But go for a dark brown, and you can cover the red.

Does Ash brown neutralize red tones?

Red hair is striking and bold, but sometimes you want to reduce red tones for a different look. Ash shades, which are cool toned, can neutralize the warmth. Choose a semi-permanent ash hair color that is a similar shade to your natural or dyed hair.