Resorcine for orange from Primuline, etc.
"The Dyeing of Cotton Fabrics" by Franklin Beech
Treatment consists of frequent soap-and-water washings, and the application of boric acid, resorcin, and corrosive sublimate lotions.
"Essentials of Diseases of the Skin" by Henry Weightman Stelwagon
The following are well-known synthetic indicators: hacmoid, obtained from resorcin and sodium nitrite, resembles litmus.
"Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 4" by Various