From WordNet (r) 3.0 (2006):
iridescent
adj 1: varying in color when seen in different lights or from
different angles; "changeable taffeta"; "chatoyant (or
shot) silk"; "a dragonfly hovered, vibrating and
iridescent" [syn: changeable, chatoyant,
iridescent, shot]
2: 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"
[syn: iridescent, nacreous, opalescent, opaline,
pearlescent]