Slitherine

Just learning the game and noticed that when I clicked a unit that had a commander/leader attached to it there was a range of hexes highlighted in a lighter shade. Is this the command range of the leader? If yes, how can I deactivate the highlighting. I looked in hot keys and didn't see anything. Thanks in advance for any info or comments.

Yes it is their command range. I don't know if it can be deactivated, though.