C.I. 73000; C.I. xat Blue 1; 2-(1,3-Dihydro-3-oVo-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-one; 2,2V27;-Bis(2,3-dihydro-3-oVoindolylidene); Indigo blue; xat Blue 1; 2,2V27;-biindole-3,3V27;(1H,1V27;H)-dione;(delta(2,2’)-biindoline)-3,3’-dione;(delta(sup2,2’)-biindoline)-3,3’-dione;(delta2,2V27;(3H,3V27;H)-Biindole)-3,3V27;-dione;(delta2,2V27;-Biindoline)-3,3V27;-dione