I've been trying to set up 256 color support correctly for quite some time but it seems to never work for me so I'm not even remotely sure what I'm doing wrong.

How it looks in the terminal vs gVIM:

What I've tried so far, and just in case I use zsh (also tried with bash)

added export TERM=xterm-256color, the screenshot is the current outcome of it.

then changed it to TERM=gnome-256color, same outcome

then changed it to TERM=screen-256color (this was so I could use tmux , and yes I used tmux -2 and added the set -g default-terminal "screen-256color" to .tmux.conf . Same outcome.

, and yes I used and added the to . Same outcome. added set t_Co=256 to .vimrc , same outcome.

It's been really frustrating. I'm just not sure if I need to install additional packages or something.