FPS396 Precip Colors

Do the precip colors displayed on the GPS396 correspond to FSS Level 1-6?

Don't think so. It appears that the Nexrad has about 12 colors in the range.
How do you know how heavy the precip within a given color band is?

Flown in several of them (Weather Channel in the FBO) and I know that
yellow is beginning to be moderate on the heavier side. Orange and up
are a bit too much for the Cherokee. I've briefly been in very heavy
rain with full throttle, carb heat, and descending about 150 feet/min.
I'm not interested in going there again. The only reason I did it was
that immediately when it began, I heard a radio call about 3 miles away
from a fellow who broke out of it into clear skies. This was in about
1996. Not sure what color it would translate to but I am not anxious to
repeat the experience.
What decision making criteria do you use to determine if you will fly
within a given color band?
Will the plane fly? Can I see for at least a mile or two? Is the ceiling
at or above 3000ft? Dark Green, probably. Yellow/orange, probably not.

Compact areas of orange/red can mean Tstorms. I don't go within 25-30
miles of those.