Wow! How beautiful the cake is! I used to make cakes and went to cake decorating classes. I would do half chocolate and half vanilla as this will please those who like chocolate and those who like vanilla. The color of the icing would go well with mocha, but I don’t think everyone would like it. What’s the icing flavor? I ask because it would help to know what flavor it is to answer this question. Good job!
P.S. You could also try white cake if it goes better with the frosting. I didn’t go with a fruit because some of us are allergic to fruits. So they can eat the fruit that’s the decoration if they aren’t allergic and still have a piece of cake.