Hi,
I recently updated from Fedora 38 to Fedora 39 and noticed that Evolution reverted back to the colored Icons Look while in GNOME (from the GNOME monochromes).
I confirmed that Autodetect was enabled.
Using the Appearance preferences, I can change the preference and do see the icons change in Evolution.
I think the issue is here:
I debugged this to a change in adwaita-icon-theme packaging such that the symbolic icons located under 16x16/actions are no longer there in the Fedora 39 / GNOME 45 version of Adwaita Icon Theme.
# from /usr/share/icons/Adwaita
$ sudo rpm -qf {16x16/actions,16x16/apps,16x16/categories,16x16/devices,16x16/emblems,16x16/emotes,16x16/legacy,16x16/mimetypes,16x16/places,16x16/status,16x16/ui}
file /usr/share/icons/Adwaita/16x16/actions is not owned by any package
file /usr/share/icons/Adwaita/16x16/apps is not owned by any package
file /usr/share/icons/Adwaita/16x16/categories is not owned by any package
adwaita-icon-theme-45.0-1.fc39.noarch
adwaita-icon-theme-45.0-1.fc39.noarch
file /usr/share/icons/Adwaita/16x16/emotes is not owned by any package
file /usr/share/icons/Adwaita/16x16/legacy is not owned by any package
adwaita-icon-theme-45.0-1.fc39.noarch
adwaita-icon-theme-45.0-1.fc39.noarch
file /usr/share/icons/Adwaita/16x16/status is not owned by any package
file /usr/share/icons/Adwaita/16x16/ui is not owned by any package
If I copy the files to mimic the packaging for Fedora 38/GNOME 44, Evolution Icons Look Autodetect feature works as expected: on GNOME, use the monochrome icons; everything else, use the colored icons.
If this is a Fedora packaging bug, let me know.