Details on the Red "Stall Zone" -- with RED PUSH DOWN Chevrons that remain (only) when the AOA is at the Critical AOA or beyond,
Yellow Push Down Chevrons, and all Green lines are removed from the display in the Red "Stall Zone" indication.
The highest AOA displayed is only ONE Red Chevron remaining at the top of the rectangle.
the Yellow "Caution Zone" with YELLOW PUSH DOWN Chevrons that remain along with the Red chevrons when the AOA approaches near the critical AOA.
Green Lines are removed sequentially from the display rectangle as AOA increases up to the Yellow "Caution Zone" indication.
the Green "Safety Zone" has green lines that are either fully filled in (during low angle of attack flying scenarios)
or only SOME of the Green lines are removed as AOA increases towards the Yellow "Caution Zone"
Note the various AOA Settings (and airspeeds) that could be matched to this AOA display rectangle in order to achieve
AOA for Best Endurance (Time Aloft)
AOA for L/D Max (Best Glide - Range)
AOA for Carson Cruise (Most efficient use of the "next" fuel flow in knots per hour to achieve the "next" increase in speed in knots)
These AOA settings for various Best Endurance, Glide, etc effects are not shown to scale on this image, but are shown "in order" from top to bottom on the rectangle AOA display.