Mac Tips & Tricks #8: Changing application icons

There are many reasons why you might want to change an application’s icon. In my case, I wanted to be able to distinguish the stable IntelliJ IDEA 11 version from an early access 11.1 build:

Here’s how I changed the default (blue) icon to the new (pink) one:

First, reveal the application’s installation location in Finder (from the Dock context menu: Options » Show in Finder). From within Finder, invoke the context menu on the selected application, and Show Package Contents. Locate the icon file (*.icns) inside Contents » Resources. Make a backup copy, edit the icon in your favorite image editor (I simply overlaid a red color filter in Acorn), and save it as a *.png.

Now comes the tricky part: Apple’s icon format includes more than just an image, it actually contains a collection of images in different sizes, resolutions & states. To create a new *.icns file, launch Icon Composer (which ships with OSX). Open the original application icon to check which sizes your new icon should support:

Create a new file, drag & drop your edited *.png to the required image size containers, and save the result. Re-launch your application – tada!