This is real edible gold leave applied to the cake. There isn't really any metalic colouring that replicates it quite as beautiful as the real thing!
AI actually don't think it's gold leaf. Golf leaf is veeeeeery shiny. Like foil basically. This looks like gold luster dust mixed with vodka and painted on. While it's got some sparkle..it really is rather matte in finish. ( I know oxy moron).
ANot my picture but this is what gold leaf looks like [IMG]http://cakecentral.com/content/type/61/id/3218501/width/200/height/400[/IMG]