1H-Indolium, 1-[4-[5-[7-(2,3-dihydro-1H-indol-1-yl)-2-(1,1-dimethylethyl)-4H-1-benzopyran-4-ylidene]-1,3-pentadien-1-yl]-2-(1,1-dimethylethyl)-7H-1-benzopyran-7-ylidene]-2,3-dihydro-