I have this working AppleScript that sets a label. But it asks me to select the file.
Question: how do you specify a path to the file that you want to change the label index to, so you aren't prompted
set myPath to (choose folder with prompt "choose")
tell application "Finder"
set label index of myPath to 2
end tell
Try this :
set myPath to "/Users/John/Desktop/Somefile" as POSIX file as alias
tell application "Finder"
set label index of myPath to 2
end tell