Goodnight and Joy Be With You All

Also the long slits in the bottom of the robes they're wearing, some Hanfu styles from the Tang Dynasty and onward do have slits but they were one on either side, and possibly one at the back, more commonly seen with round-collared robes (though not always).

Here Wen Kexing has on a quling (turtle-neck collared) undershirt which is seen in Han/Weijin Dynasties, but then the white robe has a flipped out collar. A-Xu's entire outfit is...lol, I think he's purposely wearing his collar loose like that to portray that he didn't really care about his appearance but technically no collar should be so low as that light-blue robe he's wearing. I don't think that robe actually has a defined collar, the fabric is just loosely gathered but there's no collar "cuff".

In this pic, Wen Kexing has a round collared robe which is seen in Tang, Song, Ming, but then the sleeve is like a half-shoulder vest rather than full sleeve, and that's also not seen in any Hanfu styles.

...Or is that one robe? Is the sleeve connected to that shoulder piece? Because it looks like the robe he has underneath is red (from the collar). I can't tell, but either way, that shoulder design is not a style found in any Hanfu of a particular dynasty.

This couple's wedding outfit is influenced by a mix of Song and Ming Dynasty. She's wearing green, usually seen in Song Dynasty, but her collar is a criss-crossed collar which would be Ming (Song would be like pic 3 where the woman is wearing a low-collared top rather than a high-collared robe). She's missing the "xiapei (霞帔)" which is that strip of fabric draped on the shoulders (pic 4), but it looks like the costume designer put a strip of red along the collar to give an illusion of wearing xiapei.

For the groom, rather than the official round-collar robe he's wearing a cross-collared robe, and his red is more of a blue-ish tint. Usually wedding robes, if red, are a bright red (literally called "China red" in China, xDD).

For this pic below, it's a 1-piece robe with collar piece going across the chest, then straight down from the waist. It could be a Tang or Song style Hanfu, but the sleeves, the belt, and the overall fit of the clothing isn't quite right.

The Untamed made a lot of their clothes really form-fitting against the actors, that's actually not a good fit for Hanfu in general. You want a nice loose fit, even if the clothing is "form-fitting" it's not meant to stick to your frame. Because of this, the clothing in the Untamed always appear a size or two too small (Word of Honor did a better job of sizing their clothes). If they were wearing today's clothing then it's no problem, but for Hanfu it's too tight >_< Then again, that's probably just the style they were going for so ¯\_(ツ)_/¯

This black jacket/vest definitely was just created for a "cool" aesthetic. Xianxia/Wuxia shows love doing this broad shoulder vest garment, in actual Hanfu there ARE garments that look similar but these shows really run with it.

Here, Jinguang Yao (it's Yao, right?) is wearing a round-collared robe which was popular in Tang, Song, and Ming. The outer jacket and the material (it looks like brocade rather than soft silk) makes me lean towards Ming Dynasty for this outfit.

It also has an emblem piece on the chest which makes me think of the Mandarin Square robe during the Ming Dynasty (work attire for court officials) except: 1) Mandarin squares are embroidered separately then sewn onto the robe, this looks like it was weaved into the fabric 2) Mandarin Square robes in Ming Dynast were red 3) This emblem is round instead of square

So I would say they took inspiration from the Mandarin Square robe but changed aspects to make it fit into the show better (I think the show kept most characters in lighter colours to contrast with Wei Wuxian's darker, bold colours).

There's also things like the buildings, props, etc. to consider if we were to really dig into dynasties. And the hair styles, that half-up half-down thing is purely for aesthetics because in history they wouldn't wear their hair like that (especially considering their background).

There was a short period during the Jin/North-South dynasty when some men did wear half their hair down, but that was ONLY because that period of time was notoriously chaotic and the "rules" specifying appropriate behaviour in society had crashed (礼崩乐坏). Essentially, if you were a "civil" man (particularly with some education from a wealthy family) all your hair is tied up at 15 yo, and at 20 you get your guan (hair piece) ceremony symbolizing you're now an adult.

For women, pre-marriage you can leave some hair down, but tied in the back, not loose. After marriage it all gets tied up.

Leaving hair loose would basically get you labeled as rude, disrespectful, uncouth, uneducated, crazy, you get the idea.

But in shows like this it's a nice aesthetic when they're doing martial arts moves and the hair is flying around, so these days it tends to be the go-to hairstyle for xianxia/wuxia shows.