Bug: theme-color doesn't work as expected

**Describe the bug**

According to the [code](https://github.com/cheeaun/phanpy/blob/5d6a43e5d2230077ff958c4e4864470995c0ee4e/index.html#L21), the `theme-color` or navigation bar color of the PWA should be the same color as the header bar, but it's not in my case.

- Which site: dev.phanpy.social
- Which site version: 2024.06.23.5d6a43e
- Which instance: N/A

**To Reproduce**
Steps to reproduce the behavior:
1. Go to dev.phanpy.social
2. Install it as the PWA
3. Switch dark/light mode and check the navigation bar color
4. See error

**Expected behavior**
The navigation bar color should be the same color as the header bar.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Smartphone (please complete the following information):**
- OS: Android 14
- Browser: Chromium
- Version: 126

**Additional context**

Start with the theme-color declaration in index.html at the linked line, then reproduce the issue on dev.phanpy.social as an installed PWA using Android 14 and Chromium 126. Verify dark and light mode navigation bar colors against the header bar; done means they match in both modes.

Written by the indexing model from the issue text.