Why did Windows 7, for a few months, log on slower if you have a solid color background?

Submitted ⁨⁨2⁩ ⁨weeks⁩ ago⁩ by ⁨neme@lemm.ee⁩ to ⁨windows@sopuli.xyz⁩

https://devblogs.microsoft.com/oldnewthing/20250428-00/?p=111121