The covering on the board under the cake should be very neatly done. You can use fabric, feathers, sea shells and etc. Around and under the cake to accent and make a better presentation of your sugar art. Does the covering on the cake board coordinate with the design on the cake 7. A copy of a cake out of a book - is not being creative.
Judges look for original ideas.
But, if a judge does not like the colors you chose - you may not get top marks. It is a personal thing with each of us. I personally am not drawn to cake designs in very bright colors. For instance a two layer round cake iced in bright lemon yellow with orange and blue flowers with leaf green leaves. It screams at me to get out eh sun glasses.