Familiar Wig

The Clothier sells this set, and what you are buying is nothing. Each piece displays your character's default appearance for that slot, and because it goes in a social slot it hides whatever armor you have on underneath. The wig shows your hairstyle, the shirt and pants show the plain clothes you started the game in. The armor keeps working. It just stops being visible.

Most players buy the wig and leave the rest. Head armor normally overwrites your hair, so any style you paid the Stylist for vanishes the moment you put a helmet on. The wig gives it back, dye included, with only Twilight Hair Dye refusing to show through. It has a second use too: an accessory that renders on your head, like the Obsidian Skull, is normally hidden by real headgear, and the wig lets it be seen instead.

The shirt and pants ignore dyes completely, including the ones handed out for Strange Plants, so the only way to recolor them is through a Dresser, which repaints your default clothes and the vanity set along with them. None of the three pieces can be displayed on a Mannequin, a Womannequin or a Hat Rack, presumably because a display stand has no character to copy from. The items also do not remember the body they were bought on, so a shirt purchased by one character can look wrong worn by another.

Wearing the full set makes you look like someone who just spawned in. Whether that is a disguise or a warning depends on which end of it you are standing on. It hides high tier armor in PvP, and it is the standard trick of anyone joining a fresh world intending to cause problems, so a suspiciously plain newcomer is worth a second look. On old-gen console and 3DS it goes further and conceals your armor under an Invisibility Potion, which normally leaves armor showing. Enemies are not fooled by any of it and will keep attacking you exactly as before.