Bulk Changing Application Icons on System So the question is pretty straight forward. I've disabled SIP (System Integrity Protection) and I am able to use the "copy paste" method, described in numerous tutorials, successfully to change my Application Icons. I'm wondering however if there is a folder where all the Application Icons are stored. I know that the Trash Icons and the Finder Icons are located at System/Library/CoreServices/Dock.app/Contents/Resources and that I'm able to for all intensive purposes "click and drag" the new trash and finder icons to this folder and it update the icons accordingly.

Is there a central location where all Application Icons are stored so that I can click and drag all 50 of my 'new' icons to a folder and then restart the dock app to refresh the icons?
@klanomath is close, but you actually can bulk change the icon. While the .icns file is stored within the application, it's referenced in an .xml file known as info.plist inside the Contents folder of every app. There's a string CFBundleIconFile with specifies the name of the .icns file inside the Resources folder.

While simply finding every .icns file and changing it would probably work in most cases, it's not the best practice. While it's rare for .icns files to be used for anything other than application icons, some app bundles include multiple side apps. This method minimizes risk.

If you'd like, I'll gladly assist in building an app to fit your renaming needs.