Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. colorant (material)
7. dye
8. [dye by composition or origin]
9. synthetic dye

Anotations

Scope note:

A group of blue, green and violet dyes with a molecular structure having a central carbon atom connecting three aromatic rings, used as basic dyes for wool and silk, with mordants for cotton, and in some artist paints labeled brilliant. They only have fair lightfastness.