How did you do that?
I have an iPhone so went to Settings—> Accessiblity—> Display & Text size—> Color Filters—> turn on and select grayscale.
My phone is on very very very red night filters the whole time. Blue light is the enemy ⚔️
I thought I’d try greyscale before red filters. We’ll see.
I forget how I did it. But I made my side power button a 3x tap and it goes to grey.