I got a full head of highlights and I like the color but it seems kinda blah, dull, a little ashey instead of warm. Would it be horrible if I used a semipermanent at home kit to add shine and a little bit of warmth?
It's risky, but if you really want to give it a try I would leave it in for 1/2 the time the box requires so it adds just a tad of color. The 1st time I got highlights they were too bronze and I tried dying it over with a light brown but only left it in for 10 min and it faded the bronze out a bit. However, I also had a nightmare experience years where the highlights turned green and I had to go to the salon to get a color correction.