I, like many other people, want to limit my exposure to blue light in the evening so I can fall asleep easier. My iPhone and MacBook have a feature for this, but even at the warmest color temperature I don’t think it’s effective enough. My workaround has been to use their “Color Filters” feature in the accessibility settings to set a really intense red tint and, on my iPhone, toggle it using their “Accessibility Shortcut” feature manually.

I wondered how I could easily toggle this on my MacBook though. Sure, I could manually navigate from Settings, to Accessibility, to Display, scroll down to the Color Filters section, and toggle the relevant checkbox, but I wanted something a little more convenient. I had heard about Apple’s Shortcuts app in the past; why not try using that?

So I created a shortcut to toggle the color filter. It was easy enough, there was a built-in action to do exactly that, so my shortcut just contained that single action:

At first I would manually open the Shortcuts app and click the relevant button to run it, but I later realized I could use the shortcuts command to do that:

shortcuts run "Set Color Filters"

This is when things got complicated. I like the idea of having all of my little helper utilities version controlled in “dotfiles”. I remembered that AppleScript existed and wondered if I could use that to toggle the color filter instead. I read through a dozen StackOverflow posts, tried a few things, ran into errors I didn’t know how to work around, and gave up.¹ Everything relied on how the Settings app’s UI is organized to work, which inevitably breaks because Apple is apparently indecisive about how they want the app to work.

So I went back to using Shortcuts and tried to learn a little bit more about how other people use them. You can apparently share them with other people using iCloud or as plain old files. AFAICT they use a binary-encoded plist format with a cryptographic signature from Apple. You can’t do it in the GUI, but based on this I was able to create a simple little helper shortcut to export any shortcut as a text-encoded plist:

Using that shortcuts program, you can run it like this:

shortcuts run "Get Shortcut plist" --input-path "Set Color Filters" | tee
# Alternatively:
shortcuts run "Get Shortcut plist" --input-path "Set Color Filters" --output-path set-color-filters.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>WFQuickActionSurfaces</key>
	<array/>
	<key>WFWorkflowActions</key>
	<array>
		<dict>
			<key>WFWorkflowActionIdentifier</key>
			<string>com.apple.UniversalAccess.UASettingsShortcuts.UAToggleColorFiltersIntent</string>
			<key>WFWorkflowActionParameters</key>
			<dict>
				<key>UUID</key>
				<string>C700B263-BC4F-4C18-835B-90D8454E0DC1</string>
				<key>operation</key>
				<string>toggle</string>
			</dict>
		</dict>
	</array>
	<key>WFWorkflowClientVersion</key>
	<string>3036.0.4.2</string>
	<key>WFWorkflowHasOutputFallback</key>
	<false/>
	<key>WFWorkflowHasShortcutInputVariables</key>
	<false/>
	<key>WFWorkflowIcon</key>
	<dict>
		<key>WFWorkflowIconGlyphNumber</key>
		<integer>61440</integer>
		<key>WFWorkflowIconStartColor</key>
		<integer>-43634177</integer>
	</dict>
	<key>WFWorkflowImportQuestions</key>
	<array/>
	<key>WFWorkflowInputContentItemClasses</key>
	<array>
		<string>WFAppContentItem</string>
		<string>WFAppStoreAppContentItem</string>
		<string>WFArticleContentItem</string>
		<string>WFContactContentItem</string>
		<string>WFDateContentItem</string>
		<string>WFEmailAddressContentItem</string>
		<string>WFFolderContentItem</string>
		<string>WFGenericFileContentItem</string>
		<string>WFImageContentItem</string>
		<string>WFiTunesProductContentItem</string>
		<string>WFLocationContentItem</string>
		<string>WFDCMapsLinkContentItem</string>
		<string>WFAVAssetContentItem</string>
		<string>WFPDFContentItem</string>
		<string>WFPhoneNumberContentItem</string>
		<string>WFRichTextContentItem</string>
		<string>WFSafariWebPageContentItem</string>
		<string>WFStringContentItem</string>
		<string>WFURLContentItem</string>
	</array>
	<key>WFWorkflowMinimumClientVersion</key>
	<integer>900</integer>
	<key>WFWorkflowMinimumClientVersionString</key>
	<string>900</string>
	<key>WFWorkflowOutputContentItemClasses</key>
	<array/>
	<key>WFWorkflowTypes</key>
	<array/>
</dict>
</plist>

I don’t know its full usage but the --input-path argument doesn’t actually read input from a path you specify for it (at least when the shortcut input is text, maybe it does for files?). Also, it doesn’t default to printing to stdout (probably because some shortcuts can output binary files), so if you want that you need to pipe it out, which is why I used tee above.

Anyways, great, now I have these text files I can do whatever with. Apparently some people have written nicer editing tools that work with them! Probably never going to use them, but still, that’s pretty cool. Now my only problem is to figure out how to take these .plist files and turn them back into shortcuts.

This is supposed to be pretty easy. You can’t import .plist files in the GUI, but you’re supposed to be able to pass one of these files to a shortcuts subcommand and it will do the same signature magic that the GUI does and spit back out a .shortcut file you can use.

$ shortcuts sign --help
OVERVIEW: Sign a shortcut file.

You can use this command to sign a shortcut file. It also supports signing a
shortcut in the old format.

USAGE: shortcuts sign [--mode <mode>] --input <input> --output <output>

OPTIONS:
  -m, --mode <mode>       The signing mode (anyone, people-who-know-me).
                          (default: people-who-know-me)
  -i, --input <input>     The shortcut file to sign.
  -o, --output <output>   Output path for the signed shortcut file.
  -h, --help              Show help information.

But apparently it’s been broken for a while, so people are instead using a third-party server running a version of macOS which it isn’t broken on to get shortcuts signed:

curl --request POST "https://hubsign.routinehub.services/sign" \
  --header "Content-Type: application/x-plist" \
  --data-binary "@set-color-filters.plist" \
  > set-color-filters.shortcut

Kinda weird, but whatever. The last thing I wanted to do was automatically install my shortcut. There’s a URL scheme for this:

shortcuts://import-shortcut/?name=My%20Shortcut&url=https%3A%2F%2Fexample.com

But I tried a bunch of the strategies used in GitHub code search results and nothing was working. In hindsight, maybe this is a good thing; that document I linked mentioned that there’s apparently a silent argument that will import the shortcut without any user interaction??

Anyways… this is how I spent yesterday afternoon. Not worth it, though hopefully it saves someone out there some grief.