Situation: I am sitting on a chair and there is no table right in front of me. I can see the blackboard on my right though.
Alternative situations: I am sitting in a black chair against the wall waiting for a meeting to begin. I am opposite the wall with the door and there are more black chairs to my right. I walk to the complete opposite side of the room to acquire an extra chair, and turn around to face the two tables by the blackboard.
Question: What color is the wall behind me?