I use these temporary dyes which last 24 washes. I have brown hair and I have white hairs growing now so I have to cover them up. I don't want to use a permanent dye because I am scared about root growth, I only have a few white hairs so I don't think I need a permanent dye. This works quite well. Try it. Look in the shops for a temporary dye Clairol or Country Colours. Temporary dyes are not as powerful as permanenet colour so might be safer to use over highlighted hair. After all it does wash out without any permanent damage.