Thanks for the report and the clips. I can reproduce the lack of red and we will see if we can find out why that is.
I just checked. The version of kernel 4.9 we have for internal testing is much better than the release you installed. Jamie Lee Curtis’s dress is the same colour in SDR and HDR - just a difference in lightness which is inevitable. Unfortunately there’s another issue with HEVC which will need ironing out before we can release the new version.