My sister E. recently celebrated her 28th birthday. She asked me to make a cake with either lemon/raspberry flavor combo or a chocolate/orange combo. Her color scheme was gold and blue.
I chose to do an orange and chocolate cake simply because I had the ingredients on hand. I doctored up a chocolate cake mix with lots of orange zest (probably a tablespoon?) and some espresso powder to deepen the chocolate flavor. I made a moistening syrup from The Joy of Cooking (Combine equal parts water and sugar. Heat just until the sugar dissolves. I added another 1/2 tablespoon or so of orange zest) and poured the syrup over the bottom layer of the cake.
I frosted the layers with chocolate buttercream (adding orange zest to it, too!). The decorations consist of marbled blue fondant circles dusted with gold luster dust. I probably went a little overboard with the luster dust. Around the edges I placed wedges of chocolate orange (a favorite holiday treat in our family).
Everyone had a good time at the party, I think, and the cake was a big hit. One guest had two pieces, even though he claimed that he doesn't really like cake. I think that says it all :)