Examples of such amorphous polyesters include those obtained by the polymerization of a colorant compound of Formula (I), terephthalic and,/or 2,6-naphthalenedicarboxylic acid and a branched-chain diol having the formula ##STR17## wherein R20 is hydrogen or an unsubstituted or substituted alkyl, cycloalkyl or aryl radical, and R21 is an unsubstituted or substituted alkyl, cycloalkyl or aryl radica