The most suitable black dye for this purpose is diamine black B H, diazotised and developed.
diamine blue B X. Work at the boil to shade, then lift, wash and dry.
It is probably a diamine, but has not been obtained in sufficient quantity for accurate chemical study.
Alpha-naphthol for dark reds from Primuline, greys from diamine blues, Neutral grey, etc.
diamine brown V. Dye at the boil to shade; lift, wash and dry.
Naphthylamine ether is used as a developer for blues in conjunction with the diamine blacks.
Phenol for claret from diamine cutch, and for gold yellow from Primuline, etc.
With all these peculiarities of the diamine and other direct dyes the union dyer must make himself familiar.