Assuming you are looking at our website and not at your Christmas tree, it's fairly simple: "good" METASCORES are coded in green; "mixed/average" METASCORES are yellow, and "bad" METASCORES are red. (This same color coding is also used for the individual critic and user grades.) If the numbers are too complicated to read, you can simply look at the pretty colors to tell what the reviews said.
Here's how the scores break down: