Which color of hair dye is typically used to cover gray hair?

The use of permanent hair dye is typically preferred for covering gray hair because it provides long-lasting results and is designed to penetrate the hair shaft to change the natural color effectively. Permanent hair color usually contains ammonia or a similar ingredient that allows the dye to lift the cuticle of the hair, leading to deeper and more durable color changes. This makes it ideal for gray coverage, as it offers full opacity and a longer-lasting solution compared to other types of dyes.

In contrast, temporary hair dye coats the outside of the hair and washes out easily, which is not practical for consistently covering gray hair. Semi-permanent hair dye can last longer than temporary options but doesn’t provide the same level of gray coverage, as it typically allows some of the natural color to show through and can fade with washing. Natural hair dye may offer a more organic approach, but it does not guarantee the same level of gray coverage and longevity as permanent formulations.