Summary

On Windows 10, with a 125% UI scale, KeePassXC 2.7.5 updated the colourful tray icon (for locked and unlocked database). It is now a bit smaller, and a bit blurry, even after a computer restart. The monochrome tray icon did not change, and this one seems OK.
I reinstalled KeePassXC 2.7.4, and the colourful tray icon has a better dimension. I don't know if you have similar feeling about that...

Examples

The 2.7.5 colourful tray icon:

The 2.7.4 colourful tray icon which, for me, seems better:

Regards,