I would like to start by saying that this is a friendly game jam with no prizes. People shouldn't be too hung up on the scores and try to follow the jam rules to the best of their ability.
That being said I think it's just the alpha channel rule that seems to lead to confusions. Without it the rules are simple:
You only ever display 2 colors on screen at any given time, regardless of the colors or if they change throughout the game = 5 stars.