Lithol
noun
Lith·ol
variants:
or less commonly lithol \ ˈliˌthȯl , -ōl \
Definition of Lithol
: any of a group of organic pigments most of which consist essentially of salts of difficultly soluble azo compounds
In painting the Harvard murals, Rothko used an organic pigment called Lithol red that is readily destroyed by light.— Edward J. Sozanski, Chicago Tribune, 22 Sept. 1988
—formerly a U.S. registered trademark