Measuring perceptual isoluminance - minimum motion

OS (e.g. Win10): Win10
PsychoPy version (e.g. 1.84.x): 2020.1.3
Standard Standalone? (y/n) If not then what?: y
What are you trying to achieve?: Create a minimum motion task to test perceptual isoluminance (based on Cavanagh, et, al 1984 - http://wexler.free.fr/library/files/cavanagh%20(1984)%20perceived%20velocity%20of%20moving%20chromatic%20gratings.pdf)

What did you try to make it work?: I am trying to make a rotating windmill of alternating red and green, such that when the two colors are perceptually isoluminant, the direction of the windmill spin changes.

What specifically went wrong when you tried that?: I’m not sure how to 1) create a rotating windmill stimulus, and 2) how to make the luminance for one of the colors (while the other is fixed) adjustable, from the participant’s point of view, and then record the final luminance.

To change luminance, I am trying to modify this piece of code: contrast - How to use method of adjustment in Psychopy? - Stack Overflow
But I don’t know how to adjust luminance for one stimulus. I think it would be easiest to rotate one windmill with fixed luminance, and overlay it on a circle with adjustable luminance. Just don’t know how to implement this.

So sorry this is a very vague question. If I could make a windmill stimulus that is always rotating at the same speed, and unrelatedly, adjust luminance for one of the colors, that would be wonderful. I just don’t know how to get started, and haven’t found any good demos online. Thank you so much.