The greyscale screen time hack works best when you don't have to think about it. Automation is key. While you can build automations yourself using the native iOS Shortcuts app, it comes with limitations. Here is a breakdown of your options.
The DIY Route: Apple Shortcuts
You can use the native Shortcuts app to trigger Colour Filters. For example, you can create a personal automation that turns greyscale on at 9 pm and off at 7 am.
Pros: It is entirely free and built into the operating system. Cons: It is notoriously clunky to set up. Creating per-app exceptions (like making the Camera open in colour and revert to grey when closed) requires building complex 'Open App' and 'Close App' scripts that often misfire or get stuck.
The Dedicated Route: StayGray
StayGray is a dedicated utility built specifically to solve the friction of greyscale management. Instead of building logic scripts, you just toggle switches in a clean interface.
With StayGray, setting up app exceptions takes three seconds. You tap the apps you want to keep in colour, and StayGray handles the transitions flawlessly in the background.
Handling the 'Colour Break'
Sometimes you just need colour for a few minutes to view a specific photo or check a map, and then you want it to go back to grey automatically. In Shortcuts, this requires complex timer logic. StayGray has a built-in 'Colour Break' feature that handles this with one tap.
Location-based triggers
If you want your phone to be grey at the office but colourful at home, Shortcuts often requires manual confirmation via a notification when you cross a geofence. StayGray can handle location-based transitions much more smoothly.
Which should you choose?
If you are highly technical, love tinkering with logic chains, and only want a simple time-based toggle, Shortcuts is a great free option. If you want a seamless, set-it-and-forget-it system with reliable app exceptions and no coding required, StayGray is the clear winner.