I suddenly regret the sombrero point a few toots back*. To be clear, even if production has taken several creative liberties with this hanfu that hat _is_ of a traditional Chinese model. It's basically a round shade with a hole at the top for the wearer's topknot. That point at the top is the character's hair.
(*follow the tags if you missed it)
Production is regularly fanning out from historically correct costuming, ending up somewhere between "Document everything and handspin the thread!!!" and "I don't care if they didn't use sombreros! I think sombreros are _stylish_ and will put one on every imperial guard!!!". So I doubt Jinglang's pleated collar and form fitted bodice are actually Tang period, but _dang_ they look good!
One thing that's fairly consistent in C-drama is that the more serious the situation, the darker the costumes. This is a prime example - even his guan is black. And the costume designer took the premise and ran with it! Two colours, black and gold, and embroideries that both give the character wings and enhances how thorny the situation is.
(Side note: doesn't this actor look a bit like Vincent Price?)
Thanks for having the children writing their script like children! (Not always a given in any kind of production - time constraints and similar demands often means an adult draws the basic stuff and the child actor draws a line here and there.) It's also a bit cute that they're practicing the character 'xue' - 'learn/study'.