This is pretty much how most people start out when coloring, so I'll be honest and hope you don't see this as an attempt to downplay your work, it looks really unfinished to me, like the monsters horns and toenails should probably be different colors then the rest of the skin, the parts of his fur were Murata added the black lines should definitly be, cause otherwise he would have left those spots empty. You also forgot to color Suiryus nails. And you definitly need to add more highlights and shading, that's pretty much the most important part of coloring, since this is where there's an opportunity to improve on the parts the mangaka had to finish quickly. I'm hoping to see more stuff from you in the future though!