What color do I paint on the end of the divider wall between rooms?

Sometimes between two rooms there is a partial wall to help visually divide the spaces. At the end of that partial wall is usually a 4-5 inch wide section that doesn't seem to belong to either room. What color does that get painted? First, I look at what the spaces are. If one is a dining room and one is part of a more open floor plan, I'll paint that little section of wall the color of the open floor plan. If one space is more defined, such as an office or dining room, I'll keep that color "inside" the room and not have it creep out of its space. If it is not clear which space is more defined and should keep its color inside it's walls, then I may take another approach. I decide which room I will spend more time in and use that color to wrap onto the end of the partial wall. There is no right or wrong decision, just don't divide the narrow space in half and use both colors. Yes, I've seen that!