How to reset default sidebar favourites icons in Finder?

Solution 1:

How did you restore permissions? Manually, or did you use the "Repair" feature in Disk Utilities?

Restoring from a Time Machine backup from before things went bad should work.

One thing you might try before restoring is to delete the Finder preferences. ~/Library/Preferences/com.apple.finder.plist then relaunch the Finder (Hold Option while selecting the Finder icon in the dock). The preference file will be regenerated with the system defaults.

Solution 2:

You probably restored your preferences (not permissions) by deleting com.apple.finder.plist, right? You'll also want to take out one more file, which handles the sidebar, then reboot:

rm -rf ~/Library/Preferences/com.apple.sidebarlists.plist

It probably wouldn't hurt to Verify Permissions via Disk Utility either (since you mentioned them).