Interesting. Sadly, it says, "you can only read". Whereas other files, on the same card from the same session don't have that tag checkbox checked (because I didn't click on the lock icon for those images while the card was in my camera), have read/write access. I have been "locking" photos in camera for the longest time as a way to mark my favorites and have never had this problem. That said, I usually employ a different workflow that involves me not having to color-tag "locked" favorites.
Is there any workaround for this?