I did the best I could to use the same colours as I did in the patterns for Sweetie Belle and Rarity, and I think I succeeded. But there is a possibility that one or two colours are different from the other two. But it is a cute picture and I really like these two unicorn sisters, they are so cute together.
Link to the colour key: [link]
Link to my blog: [link]
UPDATE: I know that the colours for Rarity is wrong in this pattern, I've updated the other pattern I have of her but I've missed to change this one. I will do it though, but if you still want to do ut check the Rarity pattern to get the right colours or choose your own. I don't know how the colours on Sweetie Belle will turn out though so be careful.