The Collaborative International Dictionary
roseine
magenta \ma*gen"ta\ (m[.a]*j[e^]n"t[.a]), n. (Chem.) An aniline dye obtained as an amorphous substance having a green bronze surface color, which dissolves to a shade of red; also, the color; -- so called from Magenta, in Italy, in allusion to the battle fought there about the time the dye was discovered. Called also fuchsin, fuchsine, rose["i]ne, etc.
2. The purplish-red color of magenta.
Wiktionary
roseine
n. The dyestuff magenta.