Claim: Tropaeolin or azo dyes list at least twelve dyes classified by C.I. names and indicator properties, used for dyeing wool, silk, and for coloring cosmetics.
Evidence: Tropaeolin is the retained name for some azo dyes from the industrially applied group of acid dyes used as pH indicators. Tropaeolin O
(Resorcingelb) Tropaeolin OO
(Orange IV) Tropaeolin OOO1
(Orange I) Tropaeolin OOO2
(Orange II) Tropaeolin D
(Methylorange) Tropaeolin G
(Metanilgelb) Tropaeolin RNP
(Resorcinbraun)