10 Nov 2020
If your commander has no colors in its color identity, you pay no life to activate War Room's last ability.
10 Nov 2020
If you don't have a commander, you can't activate War Room's last ability at all.
10 Nov 2020
Color identity is set before the game begins and doesn't change during the game, even if your commander is in a hidden zone (like the hand or library) or an effect changes your commander's color.