Launching Helix with default theme in tmux causes unexpected change in colors

Hi,

I'm new to both using Helix and terminal multiplexers in general, so I'd appreciate some help with this. When I launch Helix without tmux, I see the default theme with a purple background, which I like:

But when I launch it using tmux, even with the -2 flag, Helix does not display the same color scheme:

I have tried making a config.toml file with an [editor] section and set true-color to true, but that didn't appear to help. How can I use the default theme with tmux? I'm using GNOME 47 with wayland on Fedora, in case that matters.

Any post I've seen involving Helix, tmux & colors seem to be with custom themes, so I don't know which threads are relevant to this, if any.___