Themes
ex5 ships a dark and a light palette, both taken from the ex5.ai design tokens so the terminal and the site use the same colours. The terminal follows your background: dark by default, light when the terminal reports a light background.
Custom themes
UI preferences live in ~/.ex5/tui.toml. Tokens you do not set fall back to the built-in palette.
The full token reference is not published yet. Until it is, the built-in palettes are the reference — ask ex5 to read them rather than guessing token names.