To bring this magical Fairy kingdom of Witchcraft to life, I would use colors that would emphasize the enchanting nature of the scene. I would use warm colors like pinks and yellows to create a vibrant and cheerful atmosphere. The greenery of the forest can be painted with different shades of green, dark blues, purples and browns. I would use dark blues and grays to create shadows and depth, while lighter blues can be used to make the sky look light and airy. The marble Palace would look breathtaking when given a white or light grey base, and some beige and light blue or pink colors added carefully to bring out the details. Finally, I would use a sprinkle of sparkles and add a few glitter touches to the fountains, statues, and drawbridge to bring out the true magic of the kingdom.