What type of dyes involve soluble metal salts like lead, silver, and bismuth producing colors on hair fibers?

Metallic dyes are a specific category of hair color products that contain soluble metal salts such as lead, silver, and bismuth. These metal salts react with the hair's natural pigments and can produce varying shades depending on the original color of the hair and the specific metal used. The unique aspect of metallic dyes is their ability to build up on the hair over time, which can lead to darker and sometimes more intense color results with repeated applications.

Unlike permanent dyes, which use chemical reactions to create changes in hair color at the structural level, or temporary and natural dyes that often wash out more easily and do not involve these metallic compounds, metallic dyes specifically leverage the properties of metals to achieve their effects. This characteristic is crucial for distinguishing them from other hair coloring methods. However, due to safety concerns related to the use of metals in hair coloring, metallic dyes are less commonly used in salons today compared to other options.