[blahlabs]

Could you share how you achieved activating greyscale automatically? Was it Android or iOS?

I would love to be able to do this but couldn't find a way on GrapheneOS.

[chris_pie]

Latest Android has that built-in as a "Night Mode". You can also set a schedule or have it enable while charging

[HPsquared]

It's a Samsung, Android phone. I used "Modes and Routines" which allows to set greyscale (and silent mode etc.) and automate triggers (such as time of day) to activate a "mode".