This is new in the last four days.
With Intel Skylake/Modesetting, everything is now red. Reverting to 1.18 fixes the problem, as does reverting the last few days of commits.
https://patchwork.freedesktop.org/patch/101630/ fixes this.
Confirmed. That does fix it. Thanks!
*** Bug 97167 has been marked as a duplicate of this bug. ***
*** Bug 97209 has been marked as a duplicate of this bug. ***
Pull request submitted for the fix: https://patchwork.freedesktop.org/patch/102414/
*** Bug 97246 has been marked as a duplicate of this bug. ***
Author: Michel Dänzer <firstname.lastname@example.org>
Date: Fri Jul 29 17:38:21 2016 +0900
xfree86/modes: Handle no palette case better in xf86RandR12CrtcSetGamma