Ariel is quite an unusual character as she has a variety of costume options. This breakdown is based on her mermaid form but would still work for her other dresses.
Character & Film
Ariel from The Little Mermaid.
Theme, Colours & Decorations
Under the sea or beach.
Sea blue, turquoise, cyan and green.
Variety of sea creatures, crabs and fake sand.
Alternative & Potential Male Characters
Lilo, Jack Sparrow, Peter Pan or Captain Hook
Part of Your World by Jodi Benson
Under the Sea by Samuel E. Wright
Fireworks by Alan Menkin
Hawaiian Roller Coaster Ride by Brittni Paiva
Fathoms Below by Ship’s Chorus
Pirate Treasure Hunt
Four Corners: Under the Sea, Pirate Cove, Eric’s Castle, Sunken Ship