I would color this beautiful image with soft and vibrant colors. The princess and her throne can be painted in soft pinks and purples. The castle can be shaded in white and pastel pinks, maybe with light blue accents to emphasize the fairytale atmosphere. The trees and flowers behind the castle should be painted in shades of green and yellow, with orange and pink accents. To add a magical touch, I would add some sparkles and stars in the sky. Overall, this would be a beautiful and magical scene for any coloring page.