I try to setup `night light mode` in order to filter blue color on my #OpenBSD #Xenocara but, xrandr --gamma does nothing on X but seems to alter color on ttyC*. At least, xgamma(1) does work if I launch a Xephyr window. I don't know where to dig now, if it's driver dependant and if it supposed to work with my Intel HD Graphics 520.
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@_xhr_ That do the trick ! Thanks !
The code is actually very simple and seems to do what I thought I could do with a simple `xrandr --output $disp --gamma 1.0:1.0:0.7` for example.
I didn't think I would have to use an external tool.