Saint Tropez is part of the Dior's Croisette Collection for S/S2012. It is a vibrant turquoise creme, opaque in two coats and dries to a high shine finish.
(indoor natural light)
Below are some similar shades from my stash. I do not have that many turquoise in my collection, I think the closest match is Kiko 344 which is a tad darker than Saint Tropez.