I think I've encountered a bug with the nvidia drivers in Ubuntu 17.10.
When I remove nvidia-384 using sudo apt remove nvidia*, colord seems to stop being able to detect my monitor.
I reinstalled nvidia-384 and I noticed this error while it tried to reinstall:
dpkg: error: version '-' has bad syntax: revision number is empty
I'm not sure what it means, but here's a snippet of my terminal during the install:
update-alternatives: using /usr/share/nvidia-384/glamor.conf to provide /usr/share/X11/xorg.conf.d/glamoregl.conf (glamor_conf) in auto mode dpkg: error: version '-' has bad syntax: revision number is empty update-initramfs: deferring update (trigger activated) INFO:Enable nvidia-384
This is the second time I've gotten that error, after reformatting 17.10 a couple of days ago. 'colormgr get-devices' returns no devices.
Also 'colormgr create-device D2757 temp display' returns:
could not check org.freedesktop.color-manager.create-device for auth: GDBus.Error:org.freedesktop.PolicyKit1.Error.NotAuthorized: Only trusted callers (e.g. uid 0 or an action owner) can use CheckAuthorization() for subjects belonging to other identities
That's as far as I can go with this problem. I'm out of my depth in resolving it any further.