Complete color wheel generated at each sweep of 360 degrees. Upper cardinal is red at 0 and 360 degrees. Lower cardinal starts and ends at yellow. Both change with the full color wheel in between. Sets Y to sine and X to cosine of degrees to generate the same cycling circles.
Cardinals painted by Kathy. Male is red, female yellow-green (sexual dichromatism) but, unlike cardinals, the painted birds cycle through the full spectrum of colors. Notice that the motion of Y position slows down at ends and is fastest near 0, as in a pendulum and spring motion (a sine function). That's what the sine function does, cycling or oscillating indefinitely. Accompanies my demo of sine wave resulting from circling motion (uses no trig): https://scratch.mit.edu/projects/500868935/
