I'm interested in enabling a monocrome (greyscale) display mode, for use at
night/in low lighting situations.
Per some search results, I tried setting saturation with xrandr but got an
error:
$ xrandr --output DisplayPort-0 --set Saturation 0
X Error of failed request: BadName (named color or font does not exist)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 11 (RRQueryOutputProperty)
Serial number of failed request: 38
Current serial number in output stream: 38
Is there a straightforward way to do this globally?
