I may have found a workaround. I looked at my grub.cf and the default "Ubuntu" entry looked like this:
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-ff6d751f-0284-4831-8972-db64642e66a2' { recordfail load_video gfxmode $linux_gfx_mode insmod gzio if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi insmod part_msdos insmod ext2 set root='hd1,msdos1' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos1 --hint-efi=hd1,msdos1 --hint-baremetal=ahci1,msdos1 ff6d751f-0284-4831-8972-db64642e66a2 else search --no-floppy --fs-uuid --set=root ff6d751f-0284-4831-8972-db64642e66a2 fi linux /boot/vmlinuz-4.10.0-40-generic rootfstype=ext4 root=/dev/sda1 ro quiet initrd /boot/initrd.img-4.10.0-40-generic } I decided that most of the above code is "unnecessary junk" ;) and reduced it to the following nice and compact entry: menuentry 'Test' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-ff6d751f-0284-4831-8972-db64642e66a2' { insmod gzio insmod part_msdos insmod ext2 linux /boot/vmlinuz-4.10.0-40-generic rootfstype=ext4 root=/dev/sda1 ro quiet initrd /boot/initrd.img-4.10.0-40-generic } In the old days I would get rid of initrd as well, but nowadays things got a little bit more complicated, so I left it there (it would save only about 1/3 of a second on boot and it is already very fast at less than 2.5 seconds). Anyway, the "Test" entry boots absolutely fine and, most importantly, the Dell monitor is now always at 1920x1200 resolution which means the top panel in Unity is NOT reset to Ambiance. It stays light, i.e. remains in the Radiance theme. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1736723 Title: GTK Theme is reset to Ambience on almost every reboot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1736723/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs