Hello, I'm a prospective 6a buyer.
My current phone allows me to tap two buttons simultaneous to toggle greyscale, I quite enjoy this feature and heavily prefer to spend most phone time on greyscale.
Does grapheneos offer: greyscale as an accessibility feature? The ability to toggle with either buttons or, say, a selection on the pull-down menu?
I see a project like this may work (?) but obviously wish to avoid 3rd party: https://github.com/dtkav/grayscale

Thank you.

Yes, greyscale is available under the accessibility options, as well as red-green and blue-yellow variants. There is a shortcut option as well, which enables a small slide-out overlay button on the lower right edge of the screen. There may be an app that allows you to configure this toggle via another gesture or icon.

@aspentremble I just noticed there is a quick tile for color correction as well, so you could simply pull down your notifications and toggle it as needed.

2 years later

So, apparently a recent update gave us "modes" (instead of just do not disturb), which has sleeping mode and can set automatic grayscale in the evening hours, it's been one thing that I really missed from stock Pixel.

Weirdly enough it broke system dark mode detection for Dark Reader extension for Firefox, it seems convinced that I'm in light mode when dark mode is set by the Sleeping mode schedule.