Maybe the color doesn't mean anything, maybe its from who the grade comes from that decides how you take it as a child. I still believe that the color red is good to have as an alarming color. So by removing it red will cause confusion in small child's heads.
Or, children don't care what color the grade is in.
When the character of a man is not clear to you, look at his friends.
I REP you if you made a good point or made a really good post.