The ratings I provided are what they use at the Perth Festival of the Maples, which I believe is the contest Bryan is entering later this week. I think it is a standard OMAFRA scoresheet for competitions.
For colour - you are trying to be on the "high" side of the colour class, meaning for medium syrup you want the closest thing to light without crossing the line into that next category. It's a fine line you're trying to walk without getting DQ'd for being out of colour class with your entry (it's happened to us and other producers we know). We normally take syrup that's on the borderline (say could be light or medium) and re-heat it for our entry into the "lower class", knowing it will darken a little and will definitely be medium.