I use 40 volumn peroxide with hair coloring to break the base on my highlighted hair.  is this safe to do? The color turns out beautiful.  My concern is that i use it on my roots as they grow out, and then on occasion, i will highlight my hair and the hair that has been dyed with the 40 volumn will be highlighted.  I honestly have never had a problem, but would like to know if you think I will have one or if you think i should be using a less volumn peroxide.  Thank you.