Indanthrone blue, also called indanthrene, is an organic compound with the formula (C14H6O2NH)2.

By dimerization of 2-aminoanthraquinone (1) under strongly alkaline conditions at 220-235 °C, the intermediate 3 is obtained in two steps, which cyclizes intramolecularly and is oxidized to indanthrone 5.

[2] It is a pigment that can be used in the following media: acrylic, alkyd, casein, encaustic, fresco, gouache, linseed oil, tempera, pastel, and watercolor painting.

As a food dye, it has E number E130, but it is not approved for use in either the United States or the European Union.

Indanthrone blue was the first example of the brand "Indanthren" (an acronym for Indigo from anthracene) introduced by BASF in 1901.