In the game, the A321 currently has a metal/gray-colored edge around the cockpit windows.
In real life, I photographed China Southern Airlines' A321 (B-6552) at ZBAD, which can be found here. (B-6552 | Airbus A321-231 | China Southern Airlines | Anlanjian | JetPhotos). The area round the cockpit windows it was pure white.
I believed the tiny upgrade will make the game more realistic.