What size will the circle have? 5 times a second fully around seems to me a bit demanding...
I would approach it the following way:
think about two hands - a black one and a red one - to take the color of your pic that start in the center out to the border your pic implies.
Then constantly draw the black one advancing the line into the read zone and the red one advancing into the black zone.
The be fast, you may precalc the cordinates for one quadrant and then just look up the values. Since hand are only one pixle, the size and number of step relate to each other... Should you run out of time - to much to do - do less steps and draw wide hands: 2 or 3 pixles wide rectangles...
If you dounle the number of coordinates, ou can avoid drawinalways from center... becasuse of points will not change color for many steps.
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