Replacing the default Apple Logo with your own is a great way to customize OS X.  This trick could also work with organizations looking to brand their Macs with their logo.

A while back, OS X Daily showed how to replace the grey-colored background with your own wallpaper.  Unfortunately, this also got rid of the Apple logo.

I liked the grey background, but just wanted to replace the logo.  This article will describe how to do that.  Take a look at some of the examples below of what I set my login window logo to:

Notice on the last two screenshots that there is some white area in the images.  This is part of the image where the alpha channel was not completely removed.  To avoid this, you will want to make certain your item is transparent (meaning any part that is not the actual image is clear and not set to another color)–PNGs typically have the alpha channel enabled.

You can even make your own using Preview‘s lesser-known Instant Alpha feature.  This is how I made the Dharma and UNSC logos (but didn’t catch every part that needed to be transparent).

Easy Approach

The easiest way to make this customization is using Deeper.  Just choose your logo and the app will do the rest!

Manual Approach

If you like to take the manual approach, the instructions are the same as found on OS X Daily, but I found that making sure the image file was exactly 428 x 248 pixels and in a .png.  You can download the Starfleet emblem that I used below:

You need four copies of this file, and they need to be named:

  • apple.png
  • apple@2x.png
  • apple_s1.png
  • apple_s1@2x.png

I don’t know why these are like this, but it works!  Once they are named correctly, just drag them into the following path:

/System/Library/PrivateFrameworks/LoginUIKit.framework/Versions/A/Frameworks/LoginUICore.framework/Resources/

and then choose to replace all of them.

Log out and you should see your custom logo at the login window!

To add even more customization, change the picture associated with your user!