Hey, my lil' sis used to have this pony! I hope you'll find the motivation to colour it later, I like how you've already hinted at the colours by colouring the linework. The pose looks very playful and there's great movement to it! If you're looking for some constructive critique, the left hind leg looks a bit unnatural raised high like that. Lowering it to the level of the corner of her cape would make the pose more natural while preserving the lovely sense of movement you've captured here.