"xcalib is a tiny monitor calibration loader for XFree86 (or X.org) and
MS-Windows. It allows you to load the 'vcgt'-tag of ICC profiles to
X-server (like MS-Windows or MacOS do) to calibrate your display."
So if you have an ICC profile for your monitor, xcalib can apply it. As
there currently is no way (to the best of my knowledge) to create an ICC
profile under OpenBSD, you have to use another OS/tools to create one.
Though my color management expert says that an ICC profile that is created
on the same machine/display but dual booted into (for example) XP is not
correct, I feel that using such a profile is still better than having none.
Works here on i386, I would appreciate some non-i386 testing.