As you might know, I use Cobalt2 for iTerm, a theme that's built for oh-my-zsh, but I didn't want to install the framework just for the theme, so I did some research and figured out how to install it without installing oh-my-zsh. Here is how.

1. Create a folder to place the theme

mkdir -p "$HOME/.zsh/themes"

2. Download the theme on that folder

wget https://raw.githubusercontent.com/wesbos/Cobalt2-iterm/master/cobalt2.zsh-theme -P "$HOME/.zsh/themes/cobalt2"
wget https://raw.githubusercontent.com/wesbos/Cobalt2-iterm/master/cobalt2.itermcolors -P "$HOME/.zsh/themes/cobalt2"
wget https://raw.githubusercontent.com/wesbos/Cobalt2-iterm/master/.minttyrc -P "$HOME"

3. Refer the theme file on your ~/.zshrc file

setopt prompt_subst
source $HOME/.zsh/themes/cobalt2/cobalt2.zsh-theme

That's it, you have the theme now installed. You might need to do some extra steps listed on the theme's Github repository to get it properly setup, but this is something you only worry about during installation time.