My mum dyes her hair dark brown, almost black but in the last 6 months lighter patches have appeared. They look copper in some lights. It looks like multi tonal highlights gone wrong as its in patches rather than throughout. I tried to attach pics but it didn't work. Will try again in a moment.
Any advice on how to fix? I help her dye her roots and tried to put some dye in just the lighter brown bits (as well as grey roots) but it hasn't made much of a difference.