> Probably both approaches are wrong. I am asking that question both in terms > of the spec and in terms of implementation details - what is the > correct/recommended approach to render multi-layered 32-bit RGBA COLRv1 data > to a non-colour target media?
My recommendation is to blend three times, each color separately.Then combine with appropriate non-equal weights. This should be correct. Perhaps, you can combine the color first, than blend using alpha.