You can turn on color filters and select the greyscale option. Your screen display will be boring without all those pretty colors. Your notifications will be grey instead of red. Your less likely to pay attention to notifications if they are grey.
Love this thank you for sharing @Russell_Mania . Do you feel the need for more content like this in the Opal app? what kind?
Can this feature be included in Opal and password locked? Set to different work sessions/times of day?
You can already do this via Shortcuts, by syncing your Opal sessions with a shortcut that triggers black and white mode. Opal FAQ | 5+ Ways to use Opal with shortcuts