Masking is one of Carnival's oldest customs. The tradition traces to European Carnival by way of French colonial New Orleans, and historically the mask let people of different social classes mingle anonymously. Today costumes are encouraged for everyone, and Fat Tuesday is the big day to dress up.
What to wear
Anything goes - jesters, skeletons, royalty, and elaborate group themes all turn up. The practical rules matter more than the concept: comfortable shoes, layers for February, and something you can move and stand in for hours.
The colors
Lean into the official Carnival colors - chosen by Rex in 1872, their meanings assigned in 1892:
Purple
Justice
Green
Faith
Gold
Power
Where to get one
French Quarter costume shops, local makers, and online sellers all work. The cheapest and most authentic option is a DIY costume in purple, green, and gold - it costs nothing and fits right in.