I decided to make some minor improvements to my OC:

It seemed like the broken horn was distracting everyone from the rest of the pony, so I decided to fix that up. I made his eye colour brighter and also fixed up the ears. I changed the colour of his vest, because the previous colour was really starting to bug me, and I removed the bands on his legs, because those looked a little weird, too.
I'm not going to change the body/mane/tail colour. I honestly don't see any problem with it. I think it looks fine.