Would any one of your squids wear something really extravagant? Stuff like mithril bracers, tentacle rings, or lace cuffs?
Generally speaking, yes! The illithids have their own fashion sense with the exceprion mainly being S'anuk. In summary, Eketh would be the one to wear things that are enchanted to enhance his magical property, as well as Lotusen.
However, in addition, Lotusen would also wear things that are vibrant or pastel for the sake of liking the color scheme. Sa'keret has very little lore, but I also remember drawing him with butterfly tattoos and giving him an earing in the inventory.
The following is a few sketches and a transcript of the writing.
Late game Eketh had more of a sense of presentable appearence out of all my Illithids. He would get nasal and tendril piercingd, bracelets and clawed rings. He also pierces his frills, but that's neither here nor there.
Lotusen has only ever bought outfitd when the party, namely the Rogue, drags them to the store. Typically they get variant and vibrant colors of fabrics and headscarves. And small accessories like flower clips. They could also get a tattoo someday.
Sa'keret, being less developed, still had some old scribble of him having a butterfly tattoed onto his back. They also had a spare earing and piercings on his frills. Generally speaking, he isn't the type of guy to wear a shirt either.