Back out of a ground war game during a killcam and as soon as your out of the loading screen, go straight to the operator menu and it should make it go away as long as you don’t go to the pre game lobby or any other menu. You’re free to then browse the operators and weapons without the filter as long as you stay only in the operators and weapons menu as loading the lobby screen will make it come back as the red filter is caused by the red background.