As for RCD demosaicing, that's my next step. The color fringing is due to the naive linear interpolation for the red and blue channels. But, with the RCD strategy, if we consider that the green channel has full coverage of the image, we could use it as a guide to make interpolation better.
Consider a color histogram, then the logo (showing color oscillations) would have a wider spread and lower peaked histogram versus a correctly mapped (just the few colors plus or minus some noise) which would show a very thin but strong peak in colorspace. A a high-variance color occupation has higher entropy compared to a low-variance strongly centered peak (or multipeak) distribution.
So it seems colorspace entropy could be a strong term in a loss function for optimization (using RMAD).