Something to do with a change in how Chromium (and therefore, Chrome and Edge) renders colors.
The fix is to go to chrome://flags/#force-color-profile
and set it to sRGB.
Till Brehm. "[Fixed] Google Chrome shows wrong colors after update", FAQ Forge, March 25, 2021, https://www.faqforge.com/windows/fixed-google-chrome-wrong-color-after-update/.