I've seen the same ? asked about the exact cake before but don't know how to go about finding the post :( I've never done anything like it so can't really help with exact advice.
I may be wrong but if I have to do this & not getting any pro advice I will cover both the tiers with white fondant & spray paint top tier with yellow color or mixed with some gold luster dust and then stick some gold pearlized sugar. For bottom tier I would spray black at the bottom and yellow on top and again stick pearlized sugar to get the look. I would definitely do a test look on a rolled fondant before applying it on the final cake. I hope this helps and looking forward to hear some Pro advice on this.
It looks like gelatin sprinkles or sequins. Easy to make.Here is a link to the tutorial: http://www.karascouturecakes.com/edible-gelatin-sequins/
Looking closely at the pic I think there is very little gold color used on this. The top tier looks to have a very light peachy color base, then gold dragees stuck on. The bottom tier is most likely sprayed to get the dark to light coloring then the same dragees tossed on. It may be spray painted (airbrushed) gold over the sprinkles/dragees or dusted w/dry gold petal dusts..
To me, it looks exactly as Minileo described and it appears that the sugar used is the Wilton gold that gscout73 posted.