The Appearance category selects the interface colour scheme.
**Dark themes**
Tokyo Night, Black & White Dark, Kanagawa Wave, Catppuccin Mocha, Nord, Gruvbox Dark, Material Ocean.
**Light themes**
Tokyo Night Light, Black & White Light, Kanagawa Lotus, Catppuccin Latte, Gruvbox Light.
Preview applies immediately. Save stores the choice; Cancel restores the theme active before Settings opened. Theme accents distinguish PC, SP, the selected cell, operands, flags, and action buttons.