WordNet sense 1 (someone acting as an informer or decoy for the police):

fink, sneaker, snitch, sneak, snitcher, stoolie, stoolpigeon, stool pigeon

WordNet sense 2 (a moderate yellow with a greenish tinge):

canary yellow

WordNet sense 3 (any of several small Old World finches):

canary bird

WordNet sense 4 (having the color of a canary; of a light to moderate yellow):

canary-yellow

WordNet sense 5 (being or having or characterized by hue):

chromatic