Guerlain Mythic is a very cool-toned, very light sheer with a natural finish. It is a permanent powder that retails for $55.00 and contains 0.26 oz.
Guerlain Mythic Meteorites Voyage Powder ($55.00/$170.00 for 0.26 oz.) consists of a "blend of matte and pearly shades ... mixture of six correcting or light-enhancing colors to deliver the purest radiance." When blended and applied together, they create a pale pink powder with subtle shimmer/sparkle. Chantecaille Les Petales de Rose is more shimmery with a warmer golden sheen. MAC Lightscapade is more shimmery. MAC Light Sunshine has a bit more of a sheen and powderiness to it.