MAC Opalesse is a slightly cool-toned, light pink with a metallic finish. It is a limited edition eyeshadow that retails for $20.00 and contains 0.04 oz.
MAC Opalesse Extra Dimension Eyeshadow ($21.00 for 0.07 oz.) is described as an "opalescent white with pink pearl." It's a pale white with an iridescent pearl shimmer/sheen. MAC Defiance is lighter. I also think MAC Pink Opal is similar but perhaps less metallic. MAC Ready to Party is cooler-toned. MAC Young Venus is pinker, less iridescent.
A liquid-powder Eye Shadow with prismatic reflections in ten shimmering tints. Impact ranges from sheer crystallized light to a highly polished metallic effect. Lasts up to 6 hours.