Text in the Downloads window/panel is shown in wrong color

### Describe the bug

**It looks like this in Lepton Proton Style:**


### Expected behavior

It should look like this, which is Firefox's default and much easier to read:


### Screenshots

_No response_

### OS

Windows 11

### OS - Others

_No response_

### Firefox Version

131.0.3

### Distribution

- [ ] [Original Lepton](https://github.com/black7375/Firefox-UI-Fix)
- [ ] [Lepton's photon style](https://github.com/black7375/Firefox-UI-Fix/tree/photon-style)
- [X] [Lepton's proton style](https://github.com/black7375/Firefox-UI-Fix/tree/proton-style)

### Theme

- [ ] Light
- [ ] Dark
- [ ] Alpenglow (System: Light)
- [ ] Alpenglow (System: Dark)
- [ ] System Default
- [X] Others: (e.g. [Photon Colors](https://addons.mozilla.org/en-US/firefox/addon/photon-colors/), [Google Chrome Dark](https://addons.mozilla.org/en-US/firefox/addon/google-chrome-dark/), [Fairytale Of Nature](https://addons.mozilla.org/en-US/firefox/addon/fairytale-of-nature/))

### Theme - More Info

[Abyss Yellow](https://addons.mozilla.org/en-US/firefox/addon/abyssyellow/?utm_content=addons-manager-reviews-link&utm_medium=firefox-browser&utm_source=firefox-browser)

### `user.js` setup

I didn't touch ```user.js```

### Additional context

_No response_

Reproduce the issue in Firefox 131.0.3 on Windows 11 with Lepton's proton style and the Abyss Yellow theme, then inspect the styles affecting the Downloads window or panel. Compare its text color with Firefox's default appearance shown in the screenshots. Done means the Downloads text is readable and matches the expected default coloring without breaking the selected theme.

Written by the indexing model from the issue text.