Bullet Candles are a great choice as they have a flat bottom meaning they can be stuck to the cake board rather than into the cake. After all that work, you don't want your beautiful cake to be ruined by poking candles into it! Use a small blob of fondant or a dab of royal icing to attach them to the cake board.
These are sold individually, so you can get as many (or few!) as you need!
Black, Hot Pink, Red, Royal Blue, White