Smoothing Shampoo and Demi-permanent Color

Pixie cut blue hair
Q: Around Halloween I started using a demi-permanent haircolor to make my hair blue. (I work in an office with a creative bunch.) I kept my hair blue for several weeks until just before Thanksgiving when I was to go home for the holiday. When I tried to get the color out it wouldn't completely wash out.
I even purchased a color remover kit and followed the package directions, but it still didn't remove the color completely. I called a hairdresser friend to get help, and she told me that the problem was likely my shampoo. I use a shampoo to smooth my hair. Would this cause demi-permanent color to act strangely?

A: Actually, this is an interesting problem, and one that we hairdressers see more and more of as manufacturers improve their products to perform certain functions. In order to understand how your smoothing shampoo could make demi-permanent color hard to remove we need to understand how both the shampoo and the color work:
Demi-permanent color is generally constructed so that the color penetrates the cuticle layer into the cortex. These small units then slowly are washed out as you shampoo the hair, growing lighter and lighter in intensity until it is fully removed. However, your smoothing formula shampoo generally contains agents which help to tighten the cuticle layer and coat the exterior of the hair shaft, making the hair smoother and shiny.
This means that the color that was supposed to gradually wash out, cannot pass through the cuticle as easily. Since the effects of the shampoo are cumulative, the more you use the shampoo, the less able the color is to wash out.
What I think may have been a contributing factor to your situation is that your hair may have been more porous to begin with, and therefore was sealed much more, comparatively. Coupled with the routine use of the shampoo, you simply kept locking the color in more tightly.
In the future, you should be careful to make certain your hair is in very good condition before applying the demi-permanent color. If your hair is porous, use a neutral protein filler to ensure even coverage of the color, and a moisturizing, deep conditioner will be great as well. This should be done a day or two before you use the color.
Photo: Olga Nozdracheva/Shutterstock
See also:
Hair coloring
The different types of hair color
Temporary hair color for fun