Prismatic, iridescent, opalescent, opaline are comparable when they mean marked by or displaying a variety of colors.
Prismatic implies an exhibition of the colors of the spectrum (as when a ray of light is refracted by a prism) or of a rainbow. In its nontechnical and extended use it merely suggests a brilliant or striking variety of colors.
Iridescent implies a rainbowlike play of shifting, merging colors such as is exhibited by a soap bubble, by mother of pearl, and by the plumage of some birds.
Opalescent and the less frequent opaline imply both the soft milky quality and the iridescence of an opal.