Night Walker

Color Filters on at sunset, off at sunrise. A tiny macOS menu-bar app.

Click the eclipse: Run or Pause, name a city, flip Automatic. It leaves whatever filter type you picked in System Settings → Accessibility → Display → Color Filters alone — only the master switch and the strength move. It reconciles on a timer (~5 min) and when the Mac wakes, so sleep, DST, and the seasons don't leave the filter stuck. The timer polls; it does not schedule an extra exact sunrise/sunset alarm. Manual lat/lon is saved only as a valid pair; changing it clears a stale city label.

The bundle id com.flo.color-filter-scheduler is historical.

Build

swift build -c release                 # binary at .build/release/color-filter-scheduler
./bundle.sh                            # assemble + ad-hoc sign dist/Night Walker.app

Install (to ~/Applications + launch at login)

./install.sh

This builds and bundles the app, installs it to ~/Applications/Night Walker.app, writes a per-user LaunchAgent that launches it at login, and starts it now. Click the menu-bar eclipse; use Run to try the filter, then open Settings (the header gear) to set your city and turn on Automatic.

Test manually (headless commands)

The same binary supports headless commands for testing/scripting. --decide takes the location on the command line and does not read saved settings. --engine-status / --engine-reconcile do read saved settings. --set-enabled, --set-intensity, --reconcile --apply, and --engine-reconcile change the live filter. Invalid coordinates, non-finite offsets, or intensity outside finite 0…1 exit 2 before any live read or write.

BIN="$HOME/Applications/Night Walker.app/Contents/MacOS/color-filter-scheduler"
"$BIN" --get                                   # live enabled / type / strength
"$BIN" --set-enabled 1                          # force Color Filters on
"$BIN" --set-enabled 0                          # force Color Filters off
"$BIN" --set-intensity 0.5                      # set strength to 50% (live)
"$BIN" --decide --lat 48.137 --lon 11.575       # sunrise/sunset + on/off decision (read-only)
"$BIN" --reconcile --lat 48.137 --lon 11.575 --apply   # apply the decision
"$BIN" --engine-status                          # saved settings + live decision
"$BIN" -h                                       # help

Uninstall

./uninstall.sh                    # unload agent, remove app, leave Color Filters OFF
./uninstall.sh --purge-settings   # also delete saved on/off + location

Logs

The login-item agent writes to ~/Library/Logs/color-filter-scheduler.log (and .err.log).

Requirements

• macOS 13+ with Command Line Tools (swiftc / swift). Apple Silicon or Intel.
• Choose a Color Filters type once in System Settings → Accessibility → Display → Color Filters. This app flips the master and adjusts intensity; it doesn't pick the type.