I have just photographed a nice sky with large dynamic range and both Nikon and Canon managed nicely. Personally I prefer the feeling of Nikon on those images. Note that I cannot see colours properly (partial colour blindness) yet I insist that Nikon produces better colours on landscapes and Canon better representation of skin tones.
Here are the pictures just touched with RawTherapee:
I find the difference between the cameras interesting. It’s quite a lot down to white balance, but there’s something else too. Nice sky anyway!
I’ve processed one from each camera. Nikon first, then tried to more or less match that for the other. dt 4.3
I have yet to see anyone provide any credible evidence of CFA spectral sensitivity patterns making any actual significant difference in color rendering when used with a RAW processor that doesn’t do camera-specific hacks to mimic the SOOC JPEG look. (By default, RT does not).
In this particular case:
Not sure if you have a 1DX or a 1DX MkIII - the 1DX MkIII has a DCP color profile available in RT. Nikon D4 has no DCP profile available. If you have a 1DXIII, this would be the biggest contributor to any color rendering differences. Easily fixable via a ColorChecker and https://rawpedia.rawtherapee.com/How_to_create_DCP_color_profiles
