Why oxidative colors and direct dyes don't mix
Have you ever tried to apply an oxidative color at the same time as a direct dye (maybe as a shadow root, or as a toner at the bowl) only to find that you had to completely re do the color once you rinsed? Yeah, me too. And judging by different professional groups I’m a part - it’s happened to a lot of us.
I’ll break down why this happens, but first - let’s do a little color theory refresher:
Permanent: Oxidative colors, typically mixed with an oxidizing agent such as hydrogen peroxide to lift and deposit. The cuticle layer of the hair is opened and the color enters the cortex, changing the structure of the hair.
Demi Permanent: Your in-between of permanent and semi permanent. Usually mixed with a very low percentage of hydrogen peroxide, slightly alters the structure of the hair.
Semi Permanent or direct dyes: Typically not mixed with an oxidizing agent, these colors sit on top of the hair shaft and do not change the structure of the hair.
Now that we’ve got that out of the way, it’s pretty simple to understand why these two colors (oxidative and semi permanent/direct dyes) can’t intermingle. Because a semi permanent color is not supposed to be mixed with an oxidizing agent, the direct dye molecules are easily eaten up by the hydrogen peroxide in the permanent or demi permanent color when they overlap. This typically will alter the outcome of the band where they meet, creating a color that wasn’t intended.
In order to avoid this you need to be using semi permanents by themselves or separating them from the oxidative color. They can not coexist on a single strand in one process. In the case of a shadow root you should do the shadow root first and then go back in after shampooing and drying to apply the semipermanent color on the rest of the hair. In the case of putting a toner over a semi permanent, you need to remember what you’ve used and act accordingly. Using something like Redken Shades EQ as a toner over Pravana Vivids or Pulp Riot won’t work - it will eat all that hard work out right before your eyes and your heart will shatter in to a million pieces. (just kidding… kind of.)
Hopefully this post was helpful in getting you to understand not just the fact that it happens, but the why behind it. Head on over to my Instagram (link at bottom of page) - I’ll be covering a ton of color theory in November over there!