Another easy one to fix
The 'Enhance colors' window looks a little squashed in it's default width and also the screen position would be better if it was slightly top-right of the main interface to give more user view to the Viewer.
This is my custom width and position of this 'enhance colors' window on my Win 7 and it's how I think it could look as a default
Might I wonder that it currently has this 'squashed' look, as I describe, for the deliberate purpose of supplementing XnView users with lower screen resolutions on their monitors? Maybe not (I hope not) in this case.