Victoria's Violet Vest and her Vulture, Vernon

Victoria doesn't wear her violet vest to be vain, but she wears it for a very special purpose. She owns a tame pet vulture called Vernon, which her grandfather, a vet, gave her when she visited him in Venezuela. Violet enters a competition for the best pet in Class 1 of her primary school. It is important for her to wear her violet vest on the day of the competition. Will Victoria and Vernon win the competition, and why is her violet vest so important?