How to make custom Parall icons work with the macOS Tahoe dark Dock theme

Apr 19, 2026

macOS Tahoe can apply a dark Dock icon theme, but this only works correctly when the icon contains the right transparent or semi-transparent areas.

That creates a limitation for Parall shortcuts. If you draw text on top of the target app icon in the Parall wizard, or if you replace the target app icon with your own fully opaque custom icon, the final shortcut icon may no longer contain the transparency information Tahoe expects. In that case, the shortcut can still work normally, but the Dock icon may not adapt to Tahoe’s dark theme.

At the moment, Parall cannot reliably fix this automatically. Parall cannot safely know which parts of an app icon should become semi-transparent, and it cannot always extract a Tahoe-ready semi-transparent icon from the target app bundle. Guessing would damage many icons, so the correct fix has to come from a manually prepared icon.

The workaround

Create a custom icon that already contains the semi-transparent areas you want, then import that icon when recreating the Parall shortcut.

The important detail is this: do not erase those areas completely. Keep them almost transparent instead. A good target is about 99% transparent, or roughly 1% opacity. This leaves a tiny non-zero alpha value in the pixels, which Tahoe can use, while the area still looks visually transparent.

Step by step

  1. Find the target app in Finder.
  2. Right-click the app and choose Show Package Contents.
  3. Open Contents/Resources.
  4. Look for the app icon file, usually an .icns file. If there are multiple icon files, the main one is often named after the app. Advanced users can also check Contents/Info.plist and look for CFBundleIconFile.
  5. Copy the icon file somewhere safe, such as your Desktop. Edit the copy, not the original app bundle.
  6. Open the copied icon in an image editor that can preserve transparency, such as Pixelmator Pro or Affinity Photo.
  7. Choose the parts of the icon that should participate in Tahoe’s dark Dock theme.
  8. Make those parts dark and nearly transparent. Use about 1% opacity or 99% transparency.
  9. Export the icon while preserving alpha transparency. Do not flatten it onto a solid background.
  10. Recreate the Parall shortcut.
  11. On the icon name/label step of the Parall wizard, use the Browse button and select your prepared semi-transparent icon.
  12. Finish creating the shortcut and add the new shortcut to the Dock.

If the old Dock icon is still visible, remove the old shortcut from the Dock, quit the shortcut, then add the recreated shortcut again. macOS can cache Dock icons, so this refresh step may be needed.

Common mistakes

  • Erasing the selected areas completely. Fully transparent pixels may not behave the same as nearly transparent pixels for this use case.
  • Saving the icon with an opaque white, black, or colored background.
  • Editing the original app bundle instead of a copy of the icon.
  • Reusing an old Parall shortcut after changing the icon file. Recreate the shortcut so Parall can include the prepared icon in the shortcut bundle.

Why Parall still supports custom icons

Custom icons and icon labels still work well for normal Dock usage. The limitation only appears when you expect the shortcut icon to participate in Tahoe’s dark Dock theme.

For Tahoe dark theme compatibility, the icon itself must already contain the right semi-transparent pixels. Once you import that prepared icon through the Parall wizard, Parall can use it when creating the shortcut app bundle, and the resulting shortcut can follow the macOS Tahoe Dock theme correctly.