Her original design was pink with purple, white and green hair, and her cutie mark was a celtic swirl.
Then when G3 was reduced to “Core 7”, her colors were changed to replace Rarity (which was so wrong in my opinion) and her cutie mark was changed to a paintbrush.
You may use this!
And you don’t have to credit me, because I’m sure Hasbro still holds the copyright to the image, and this was vectored directly from a photo of the pony.
Check my MLP Stock Folder for more cutie marks.