I will make sure to do your review as soon as I finish the requests before you.
Patience, my friend.
OC: Cerulean Sky Owner: Cerulean Sky
First off; the design. I've always loved that color scheme, so I definitely have no problems with it. It is very pretty and the colors go very well together. They don't clash, and aren't too flashy. I like how that color scheme goes with the name as well. I love the mane style as well; it is really unique and pretty. So yeah, I like this design quite a bit, and have no issues with it.
Her personality. Well, there technically isn't anything wrong with the personality. It has negative traits, positive ones, and interests that reflect off the cutie mark. However, this OC has a really plain personality due to the fact that the traits chosen for her are some of the most common ones in OCs I see. I recommend adding more traits that better define Cerulean Sky. Perhaps you could use some traits often found in people with creative abilities. And a little personal touch to the personality is always nice. Aside from that, you could also pick more traits that you yourself have and incorporate them into Cerulean Sky's personality (I'm assuming the already existing traits are yours as well.)
Lastly, her backstory. Well, it feels overly tragic to me. I'm not particularly fond of OCs being orphaned for no good reason, and there doesn't appear to be any reasoning other than the fact that she gets to live under the care of Starlight. Now, you have the right idea in showing how she earned her cutie mark, but they're better ways that this can be accomplished. You could just have her be a teacher that your OC's mom hired to teach Cerulean Sky artistic things and go from there; establishing a relationship between them. Also, I don't think you should kill both of the parents, but I guess only having the Dad die would be okay, but I would like it better if they stayed alive. Keeps her a bit more normal. But I like how she earned her cutie mark in the backstory.
Overall, an OC with a great design, a plain personality that could use some additions, and a backstory that could have been written better.
Grade: B-