Late 19th century; earliest use found in The New Sydenham Society's Lexicon of Medicine and the Allied Sciences. From ancient Greek ἀλλόχροος changed in colour + -ic.
Definition of allochroic in US English:
allochroic
adjectiveˌaləˈkrəʊɪk
rare
Changeable in colour.
Origin
Late 19th century; earliest use found in The New Sydenham Society's Lexicon of Medicine and the Allied Sciences. From ancient Greek ἀλλόχροος changed in colour + -ic.