Thank you for your comments.
I changed to YCbCr444 10bit, and maybe... maybe yes, there is a bit of difference.
Actually I do not know, maybe my eyes fail me...
To understand more clearly what I mean... I have just watched the following movies (Dunkirk, War for the Planet of the Apes, Dallas Buyers Club), and the shades of dark clothes are blurred. Seems to me at least... I do not see the dress line of coats etc. Maybe it is in the material of the certain movies... but I do not know...
http://assets1.ignimgs.com/2017/05/05/sequence-03still006-1494013048239_1280w.jpg
http://cdn.collider.com/wp-content/uploads/2016/12/war-for-the-planet-of-the-apes.jpg
https://1850516970.rsc.cdn77.org/wordpress/wp-content/uploads/2014/02/Dallas-Buyers-Club-BD_14.png