You can imagine them like this:
Su Min:
Xie Yingying:
And their aesthetic, or about their clothing preference.
Su Min wardrobe was colorful—whites, blacks, blues, yellows—more gender neutral. While Xie Yingying mostly wear black, or dark color. You can guess which was which tho~
Their possible couple robes: In my mind when they get out from Golden Core Avenue they use this kind of "couple" robes.
Anyway, if you also have pic that scream "It should be Su Min/ Xie Yingying", or their "robes" you can comment on this line.
"Cultivators naturally exuded an ethereal aura, a convergence of heaven and earth's spiritual energy. Some radiated charm, others icy detachment—Su Min's presence carried a playful, almost mischievous sharpness."- This was from certain chapter.
Su Min's presence carried a playful, almost mischievous sharpness. While Xie Yingying is Icy detachment as we know in her interaction with Prince Yong's faction before she was resealed, and her interaction with other in Golden Core Avenue too.