Stop Hair Color Staining

Blonde hair with pink chunks
Q: How can I stop purple, pink, blue or green chunks of color from staining the rest of the blond hair?
I am a hairdresser, and I wanted to know how it's done because I tried it once and it stains the blond. I see a lot of people with blond hair and semi permanent colors in it.

A: I am going to presume that you are doing these color applications using a foiling method or at least a cap, in which case the problem is likely that the hair is very porous and the color is bleeding onto the surrounding hair after application when the client shampoos his or her hair later. If you aren't using a cap method or foils to apply the fashion colors, you should be.
But, the presumption is that you are, so the need here is to resolve the porosity issue. The first step is to get and use protein filler on the hair before applying the fashion color. These protein fillers are generally inexpensive and help hair color bond to the hair better by replacing and reinforcing the internal structure to which color molecules bond. Protein filler also helps to seal color into the shaft and reduce color bleed and fade-out.
Another tip would be to use a follow-up application of a clear-gloss hair color treatment. This demi-permanent application of shine enhancers will help to further seal the color into the hair and make for a better color result. These two tips combined should give you the color results you want. ou can maintain yourself if that is a major consideration, but I do not recommend trying to do this kind of color shift yourself.
Photo: Moskalenko Yuliya/Shutterstock
See also:
Hair coloring
Foil highlighting
Highlighting with a cap
Temporary hair color for fun