. . . "of 0, 1, 2, 3, or 4; and (c) forming a third reaction mixture by admixing (1) the brominated alcohol-substituted colorant, (2) a carboxylic acid of the formula R2COOH, wherein R2 is an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, (3) an optional esterification catalyst, and (4) a solvent and heating the third reaction mixture to form a brominated ester-substituted coloran" .