The Front Panels for the 7000 series cases are 570mm x 188mm (22 7/16" x 7 7/16"). The 7000X comes with the glass panel (shown on the right) and the 7000D Airflow comes with the steel mesh (on the left). The panels are fully interchangeable - you can get the Airflow panels and put them on the 7000X (or vice versa). You can get different colors - there's no reason why you couldn't put the black panels on a white case - it might actually look pretty cool. You can also switch out the panels by season - use the airflow panels for the hot season (summer here in Texas, winter in Oz) and the glass panels for the cool season (about 3 months here).
You can get the different panels on Corsair.com.
7000D Front Solid Panel - Black
7000D Front Solid Panel - White
7000D AIRFLOW Front - Black
7000D AIRFLOW Front - White
7000X Front Tempered Glass - Black
7000X Front Tempered Glass - White