[Bug]: Top padding color does not match top browser bar when enabled with vertical tabs

[Raeitus]

Pre-Submission Checklist

• [x] I have checked the existing/closed issues to ensure this issue has not already been reported.
• [x] I am using the latest supported version of the browser.
• [x] I have tried disabling all browser extensions/add-ons to rule out interference from these.
• [x] I have tried clearing the browser cache and cookies.
• [x] I have checked with a new profile and the issue still occurs.
• [x] I have provided detailed step-by-step instructions on how to reproduce the issue.
• [x] I have included relevant screenshots or console outputs.
• [x] I have checked that this problem is not occurring in the latest version of Firefox ESR.
• [x] This issue is specific to this browser and does not occur in other browsers.

Bug Summary

Top padding color does not match browser when enabled with vertical tabs

Reproduction Steps

1. Toggle Vertical Tab Bar (experimental)
2. Toggle Enable padding at the top

Expected Behavior

The color of the padding added should be the same color as the top bar of the browser

Actual Behavior

Padding color is different from top bar

Screenshots

Breeze Theme

Breeze Dark Theme

Browser Version

11.22.0

Operating System

Arch Linux

Additional Context

Arch Linux KDE Plasma 6.2.5 floorp-bin 11.22.0 from Arch Repo