Running Dynamics zones

When you record an activity wearing a Running Dynamics compatible device (RD pod, HRM-run or HRM-tri), the charts of most measured metrics (i.e. cadence, vertical oscillation, vertical ratio, ground contact time and ground contact time balance) are plotted on Garmin Connect with some nice colors which indicate "zones" (check https://media.dcrainmaker.com/images...12/image55.png).

Are these zones fixed values or based on the user's history?
- If they are based on the history, it would be nice if we could get it from the SDK (feature request? :-D ).
- If they are fixed, could someone provide me with the ranges?

Thank you!