default theme is not usable in urxvt

[ghost]

this is what i see

[jedahan]

same in fresh macos Terminal.app

[dkmar]

This is also what I see in Terminal.app. However, if I am in tmux and launch amp, then there's no issue and it appears as it should. Only outside of tmux is it unusable.

Also notable: tmux seems to strip the background color of my amp theme. The only time I've seen the background color work is in Alacritty without using tmux.