Here is a sample of themes. Add zmodule <theme> to your ~/.zimrc and run zimfw install to enable one of them.
Some themes require also installing prompt enhancement modules for them to work. So make sure to check the requirements of the theme you've chosen. They can be found in the full documentation for the theme, available when clicking on the name of the theme below.
agnoster
asciiship
bira
eriner
gitster
magicmace
minimal
s1ck94
sorin
steeef
Community themes
Ansimorph/oblong
