iridescent

varying in color when seen in different lights or from different angles; "changeable taffeta"; "chatoyant (or shot) silk"; "a dragonfly hovered, vibrating and iridescent"

having a play of lustrous rainbow colors; "an iridescent oil slick"; "nacreous (or pearlescent) clouds looking like mother-of-pearl"; "a milky opalescent (or opaline) luster"