The Cosmetic Armor Reworked mod allows for the player to wear a full set of armor for protection as well as a secondary set of armor or clothing purely for looks. This means you can have the complete protection of a set of diamond armor but look like you’re wearing a set of weak chainmail armor.
And the way the GUI works you could wear armor and simply shut off the looks of it maintaining your desired character skin! Just click the tiny box in the upper left corner of the cosmetic armor slots. It also doubles as a misdirect by making it seem like you are unprotected.
The mod works with other armor based mods as well so you can mix and match a variety of options and still maintain the same level of protection. You can even wear mob heads and get a full aesthetic overhaul without putting yourself at a disadvantage.