If I am going to place a question near each answer of each four classmates I interview, I would waste tons of unnecessary space, so I make use of colors to differentiate answers of each question.
More importantly, it is always good to ask for feedbacks. After finishing the 2.1.0 draft, I feel something wrong with my design, but I cannot tell what it is, probably because I had stared the monitor for 2 hours. I ask Tony, a friend of mine, who was also in the library, walking by me, that what is the first problem you discern from my design. He simply just said it was not easy to tell which square belongs to who. That is the problem! the squares of a particular classmate are too close to the squares of another. Therefore, I move them apart and get the current version 2.4.0.