The Ultimate L'oreal Hicolor Blue Tutorial: Mixing Ratios, Application, and Aftercare
By Marcus Vance
Can I use L'Oreal HiColor Blue on hair that has already been dyed dark brown or black?
No. Color cannot lift artificial color. Applying this formula over previously dyed hair will lift your virgin roots to blue while leaving the previously dyed lengths dark, resulting in severe banding. You must remove prior artificial dye with a dedicated color stripper before using this product.
Why did my hair turn teal or green after a few weeks?
As permanent blue pigment fades, the warm yellow and orange undertones exposed during the lifting process become visible. The combination of residual blue dye and exposed yellow hair produces green. Wash with cool water and use a blue-pigmented depositing conditioner to maintain correct tonal depth.
Do I need to bleach my hair before applying L'Oreal HiColor Blue?
No. L'Oreal Excellence HiColor Highlights contains an integrated lifting agent designed specifically to bypass separate bleaching on dark virgin hair. Pre-bleaching the hair before using this product can lead to extreme chemical damage and severe breakage.
Marcus Vance is a cybersecurity auditor and technology writer dedicated to educating the public about online safety, data privacy regulations, enterprise security, and emerging cyber threats.
