I bet the classroom walls are covered with all sorts of crap. This will distract a child.
Best thing for schools to do is take everything off the walls except a cursive alphabet and a number line. If they want to entertain the kids with ADD, on Friday put up everyone’s pictures in the cafeteria and take it off the walls by Monday morning.
I would tend to agree with you.
You actually make a very interesting point, some kids with ADHD have a hard time with patterns and colors which will distract and overload their sensory mechanisms from time to time.