background in branches, dark mode.

[Richard Kimberly Heck]

On 10/5/24 8:17 AM, Jürgen Spitzmüller wrote:
> Am Samstag, dem 05.10.2024 um 12:46 +0200 schrieb Jürgen Spitzmüller:
>> It is a general issue how inset background colors are set.
> It was a branch-specific issue, after all.
>
> Fixed in master, might get backported to stable if Riki agrees.

Cherry picked.

Riki