Red and green lines repeatedly stamps and turns by the "degrees" you set. Yellow should result, according to light theory, but the "moire" starlike patterns should be red and green. To see just a 2D disk, set X and Y 3D to 0. What degree turn makes interesting patterns?
When mixing light (as in a computer screen, "additive" mixing), red and green make yellow, because yellow is between (average of) red and green on rainbow of wavelengths. Spacekey to change background color. The thin lines, spaced a bit apart, create "moire" star patterns, which should be red and green, on a yellow disk.
