Chemical Colorants for Herbal Hair Darkening Shampoo

For a herbal shampoo designed to darken hair and cover white hair without requiring gloves or staining skin/surfaces, semi-permanent hair colorants are generally the most suitable chemical type.

Unlike permanent hair dyes that use oxidation to change hair color, semi-permanent dyes deposit color directly onto the hair surface. This makes them easier to use, less likely to cause staining on skin and surfaces, and easier to wash off spills. The color gradually fades over several washes.

Based on your requirements, consider the following options:

• SemiColor - Wood Black: This is a semi-permanent color specifically designed for shampoo or conditioner formulations. It builds color gradually with repeated use. Note that it works best with non-ionic or amphoteric surfactants and may require pH adjustment (around 9) and the use of a color fixative like ColorFix™ for optimal results and longevity.
• Semi-Permanent Hair Colorant (Natural Black): This colorant is intended for use with a specific semi-permanent hair color shampoo base. It is designed for refreshing hair color and typically lasts for about 7-10 washes.

Another option, if ease of washing off surfaces is a top priority, is Black Color EasyWash™. This is a water-soluble cosmetic colorant with special properties that make it easy to wash off surfaces. While it can impart color, its effectiveness in significantly darkening hair and covering white hair might be less pronounced compared to dedicated semi-permanent hair dyes.

When formulating, always test the colorant in your specific shampoo base to ensure compatibility, desired color result, and minimal staining.