gThumb uses my display color profile only on some images
On my first screenshot you can see same image opened in darktable and gthumb. Colors in gthumb looks dull, and this image looks completely different in color managed applications such as my web browser or darktable.
Second screenshot shows another image, in which gthumb decides to use color management, and there is no difference between colors in both applications. Note that the "apply embedded color profile" button appears in case it uses color management.
gThumb 3.12.2 compiled using this method https://github.com/GNOME/gthumb#installation
Edited by Roman Sedykh