If the markings stay the same, changing the colors to whatever you like is totally fine. ^^ If the colors are changed drastically and the markings are also altered, that's when it becomes a bit iffy because the new edit has to look enough like the old design that I couldn't approve it as its own MYO, if that makes sense! I just want to make sure the spirit of every design is respected so they're not turned into something else entirely.

As for how to get it approved, just pm me with the original + your changes and I'll let you know if it's good to go :] if it's not, I'll give you suggestions on how to fix it.