#10 Red Red Colorful Protein Filler

I didn't use this to fill my hair while coloring (I will do that next) but as a touch-up between colors. I recently dyed my hair to a 6RV over a platinum filled with a neutral brown (if it sounds...

I'm a licensed hairstylist and I knew that if I wanted to take my previously bleached/light brown hair to a dark, deep, rich red, I would have to fill it. My hair was black, then ombre, then...