Bullet Candles are a popular choice for many cake decorators when finishing off birthday cakes, as they don't need to be stuck straight into the cake, ruining the precise decorating work. They sit flat on the cake board and can be attached to the board either with a small dab of royal icing or fondant.
These are sold individually, so you can get as many (or few!) as you need!
Black, Hot Pink, Red, Royal Blue, White