What colors can you dye over 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.
How can I darken my bright red hair?
When dyeing your hair darker, you can dye over the existing color using an at-home dyeing kit. Dye your hair a dark shade of brown or black so the red hues do not show through the hair color. Shampoo your hair in warm water to remove as much of the original bright red color as possible.
Why you shouldn’t dye your hair red?
Because the molecules in red pigment are much larger than the molecules in other colors, the first few times you try to go red, the color won’t fully penetrate and stain the hair. In turn, you’ll end up with a lot of fading that can sometimes make the color look more translucent and old.