bis{N-[(3E)-9-[2-(ethoxycarbonyl)phenyl]-6-(ethylamino)-2,7-dimethyl-3H-xanthen-3-ylidene]ethanaminium} 4,4'-{[(4-methoxyphenyl)methanediyl]bis[(2-methylbenzene-4,1-diyl)(E)diazene-2,1-diyl(3-methyl-5-oxo-4,5-dihydro-1H-pyrazole-4,1-diyl)]}dibenzenesulfon