iTunes 12 blue icon
Oct 28, 2014

I'm not big fan of new icon for iTunes 12. Here is how to change it:

iTunes keep it's icon at

/Applications/iTunes.app/Contents/Resources/iTunes.icns

For iTunes 11 you can download here: https://dl.dropboxusercontent.com/u/586048/iTunes.icns

I checked this manual and app liteicon it worked for me.

But it also works if you just replace icon.

# download file
wget https://dl.dropboxusercontent.com/u/586048/iTunes.icns -O /private/tmp/iTunes.icns
cd /Applications/iTunes.app/Contents/Resources
# replace icons
sudo mv iTunes.icns iTunes_red.icns
sudo cp /private/tmp/iTunes.icns .
# drop cache
sudo touch /Applications/iTunes.app
sudo touch /Applications/iTunes.app/Contents/Info.plist
sudo find /private/var/folders/ -name com.apple.dock.iconcache -exec rm {} \;
# restart dock (may take few seconds)
killall Dock

I tested on os x 10.9.5, blue iTunes icon is from macmini having not updated iTunes