tmux displays wrong color

[bepnos]

Whenever I run this terminal inside of tmux running neofetch shows that the system only uses 8 distinct colors instead of the 16 (top row and bottom row are all the same) whereas when I run something like kitty (also tested xterm) inside of tmux this doesnt happen. Specifically for example first entry on the top row is black first entry on the second row is grey. With cool-retro-term this grey is also displayed as black.

Kitty as standalone:

Kitty in tmux:

cool-retro-term in tmux:

cool-retro-term as standalone:

I tried several settings in tmux (changing the $TERM variable etc) to try to fix this and none of them worked, which leads me to believe the issue lies with cool-retro-term and not tmux since I've also never had any issues with tmux before.