some (many?) themes have low contrast depending on terminal fg/bg

[Rudxain]

Summary

I've noticed that some themes have bad text contrast when the terminal is in "light mode" while the theme variant is dark, and vice-versa. For example adwaita-dark's command-help UI is mostly unreadable.

Even themes that are designed to use the terminal palette (such as base16_terminal #10751) have bad contrast when swapping foreground and background colors.

This is concerning to me, because it seems like a common footgun when writing themes. I've made that mistake several times while developing "omicron" (#14809), because I assumed ui.text specified the default colors for absolutely everything

Reproduction Steps

I tried this:

0. Set terminal BG to white and FG to black
1. hx
2. run :theme acid (literally the first option)
3. type :

I expected this to happen: the shown commands are easily readable

Instead, this happened: it's black text on a dark-grey background

Helix log

~/.cache/helix/helix.log

Platform

irrelevant

Terminal Emulator

irrelevant?

Installation Method

irrelevant

Helix Version

helix 25.07.1 (68c7e87)