Apple - zsh themes loaded but not working

Do you have a custom PS1 that is overriding the prompt from the theme you have selected?

1. Check you don't have any additional lines in ~/.zshrc beyond the default?

   1. Backup your .zshrc
   2. Delete all lines beyond export PATH=$PATH:/…
   3. Reload your Terminal

2. Do you have any plugins that are messing with things?

   • Check ~/.oh-my-zsh/custom/plugins/ for any additional plugins.
   • Remove all your plugins from your ~/.zshrc and reload your Terminal.

3. Check you don't have any additional lines in your ~/.zprofile?

   mv ~/.zprofile ~/.zprofile-bak
   

   …and reload your Terminal. (Put back with mv ~/.zprofile-bak ~/.zprofile)

^{Note: trapd00r and linuxonly show the same errors for me}

Do you have your iTerm profile set to report 256 colors?