Call status readily visible next to user name to avoid disturbance when you are in call or presenting mode
Red appears for all three In Meeting, busy and in call.
One has to hover over user name to understand if the person is in call or not. People tend to skip this step and call directly even if the person is in call. This causes disturbance when you are in call or presenting mode or talking. Due to poor n/w sometimes hovering does not work.
Also, the status could be readily available in contact list, just next to time.
Also, when one searches for a name, the status could be displayed there as well