I would color this picture by giving the elf a warm skin tone, such as beige with some touches of pink. Her eyes would be a deep blue and her hair a glossy golden blonde. The dress could be a shade of light blue with a little bit of sparkles and some white details. The flowers in the background would be a mix of yellows, pinks and purples, while the butterflies could be a mix of bright blues, greens and purples. Finally, I would draw the silhouette of some mountains in the background to create a more peaceful and magical atmosphere.