Darin , a stylist at Bumble and bumble Downtown Salon in New York City's Meatpacking District.

Q:My friend always dyes her own hair but this last time it turned a weird green color. Why didn't it work this time?

A: The problem could be that your friend is coloring her hair from root to end every single time, depositing too much ash coloring -- ash is used to control warmth -- on the ends of her hair. Because her hair turned green, it's probably because her ends are damaged and porous from previous color treatments. Tell her to apply the dye to her roots and not repeatedly to her ends. She can apply it to her ends as needed, but for a shorter amount of time than to her roots, near the end of the processing.