Indian yellow, also called euxanthin or euxanthine, is a xanthonoid. It is transparent yellow pigment used in oil painting and watercolors. Chemically it is a magnesium euxanthate, a magnesium salt of euxanthic acid. Indian yellow is a clear, deep and luminescent yellow pigment with a color deeper than gamboge but less pure than cadmium yellow. Indian yellow is a glycoside, a conjugate of the aglycone euxanthone with glucuronic acid, making the chromophore euxanthone much more water-soluble. Due to its fluorescence, Indian yellow is especially vivid and bright in sunlight. It was likely first used by Dutch artists. Before the end of the 18th century it was commonly used by artists across Europe. The origin of Indian yellow was unknown until 1883; most recently Victoria Finlay, a British journalist and writer about color questioned this origin in 2004.
-O936.gif)