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The matching-to-sample experimental procedure was altered by reinforcing the selection of the non-matching comparison hue rather than the matching stimulus. Six birds were trained with red, green, and blue alternatives and a simultaneous presentation of stimuli in which the sample was present at the same time as the choice stimuli. The acquisition functions began well above the chance level but displayed a very slow improvement thereafter, which was different from that shown under matching conditions. Transfer of the oddity performance was tested by substituting a yellow light whenever a blue stimulus had previously been programmed. The results from the transfer test are considered in terms of both a “coding hypothesis” and the stimulus rules which appear to govern the performance of the “oddity” task.