Is there a Notification Center icon cache? Trying to change Apple app icons but they change to default app icon
I found an answer to my issue using this AskDifferent post: Apps Icons not appearing.

I think what finally solved the issue was:


deleting ~/Library/Preferences/com.apple.dock.plist and then
Enter this command killall -KILL Dock
Restart Mac


I hope this helps anyone who is having this or a similar issue. Thanks!