The girl in the coloring page is Sunset Shimmer, and she is wearing a beautiful purple dress with a white undershirt. Her long, straight purple hair cascades down her back to her waist, with a bright purple streak near the center of her head. To finish the look, she sports a stylish purple headband that adds a hint of extra color and detail.
In regards to how to color the page, I would suggest starting with the dress, then going to the headband and undershirt, then shading the hair. I would recommend coloring the dress a deep purple shade, the headband a lighter lavender color, and the undershirt a bright white. For the hair, use a combination of alternating purple and deep blue to create a beautiful gradient and contrast. Finally, add in streak of bright magenta for the purple streak near the center of her head. This will result in a vibrant and stunning coloring page.