WPM Status States

Is there any documentation on the Status Codes for WPM?  It looks like there are only Red = Down, Red Exclamation = Critical Latency and Yellow Exclamation = Warning Latency.  For example we would expect anything equal or greater to 400 status codes on the steps to show as something other than Green = Healthy but that is what it shows. I have the link for general status codes, I was hoping to find something specific to WPM. Thank you.