Config window unreadable on black background themes

[overlord624]

When using a Firefox theme with a black background, the preferences window becomes completely unreadable. The about description and the window controls are visible as normal, but their descriptions are invisible. An example of a theme where this issue appears is https://addons.mozilla.org/en-US/firefox/addon/lavafox-v1/

[holocronweaver]

This is likely a theme issue, not a Firemacs issue. I am using FT DeepDark, which is nearly black, and can see the config menu fine.