The way to read the visualisation is:
- GREEN: This is one standard deviation and is acceptable in most cases
- YELLOW: This is between one and two standard deviations and is considered possibly too low or high
- ORANGE: This is between two and three standard deviations and is considered too low or high
- RED: This is between three or more standard deviations and is considered far too low or high
But these are indicative and the interpretation is dependent on the specific needs of the user and the person interpreting the results.