Colors above dark blue in weather radar

[Diatosta]

Has anyone seen or have any idea what weather above dark blue (level 3) in the weather radar is? In all the races I've done never seen it get above that, and the radar having 4 more levels above it would indicate some catastrophic weather.
Is it just not implemented? Could it be reserved for something like snow tracks?

 

[AutumnalGlow]

I've never seen anything higher either. Considering how hard it rains in dark blue, I don't think the other colors can even exist. They'd be tropical storms and hurricanes.

 

[JDMKING13]

I've never seen anything higher either. Considering how hard it rains in dark blue, I don't think the other colors can even exist. They'd be tropical storms and hurricanes.

If I see those type of colors I’m just going to stop and pull over!😭😭