I love the color palette! It's very calming. These are a few personal feedback. Please take them with a pinch of salt.
The crop of the dragon's tail is drawing my focus. With so much empty sky, and only 2 characters, I personally would like to see the whole of both of them, unless there is a reason for cropping for the storytelling.
I agree with Kevin about the outlines. You can try removing them, or changing the color so that it blends in more with the illustration.
It "feels" right to have standalone characters facing the right since we read from left to right. Try flipping the image and see if that works?
The tip of the dragon's tail is almost florescent. I'd lower the saturation/brightness on that a tad.
I'm assuming that beautiful blue is the dragon's local color. But when put in an environment with purple/pink light hues, it's color wouldn't remain such a bright blue. Mask the dragon with a similar purple and try different blend options to see which looks best.
Overall, lovely illustration! The way you've drawn the clouds really shows depth and vastness of the sky π