All this time I’ve been stuck using vim in 8-bit color because I thought my terminal emulator couldn’t support any higher. Turns out all I needed to do was let VIM know that I wanted pretty colors.
Step 1: Make sure you have a VIM color scheme that supports 256 color. I like the wombat256 theme.
Step 2: Tell VIM that you want 256 color by adding this line to your ~/.vimrc file:
set t_Co = 256
Step 3 (optional): Depending on your terminal emulator, you may need to also add this line to your ~/.bashrc file: