Awesome, so glad to see people analyzing the little inconsistencies of manhua like this.
While we're at it, my largest source of confusion (and one that comes up a lot) is why the nobility in similar manhua always have bright, colorful hair(and often eyes). MC's reasoning for hiding her hair in the slums is because her "hair color draws attention". This implies that colorful hair is unique to the nobility- and in fact, we have seen red, pink, blue, and blonde hair among the ruling class, and yet somehow all the peasants have some variation of brown hair.
I think this motif is a grave mistake because it implies that somehow, the nobility are genetically different from the working class(no mention of artificial hair coloration has ever come up, so I must assume otherwise). This happens so much that we never even bat an eye, and even take it for granted. If I were to look deeper into it, I would say that this is a perpetuation of some nasty, ancient beliefs, but I'll go no further.
Also, she's fooling nobody when she's standing beside a prince-type in yellow pants and a cravat.