s of the formula X ##STR40## in which R9 is defined in the same way as R6 of the formula VIII and R10 is hydrogen or hydroxyl; dyes of the formula XI ##STR41## in which X is oxygen or sulfur, R11 is hydrogen or C1 -C4 -alkyl, Y is a substituted or unsubstituted aryl radical, and n is 1, 2 or 3, the benzene ring A is unsubstituted or substituted by halogen, and the benzene rings B and D, independen