While Blood CM includes proper skies, their resolution is very low, so I've grabbed a few free skyboxes and put together replacements that would be easier on the eye. They aren't completely spot on, and not exactly hires, but they are better-than-nothing™.

Extract to your BloodCM_Finished folder, overwrite, enable autoload folder in the launcher.

NBlood - Extract to the autoload folder, enable it in the NBlood launcher (note: seems like NBlood 1.01 is required, newer builds do not load the textures).

ok @Grosnus, I'll be greedy one more time - while the first two skyboxes in this three skybox set fit like a glove, the third one just plainly sucks, and I wasn't able to find anything better - brownish mountains, AND cloudy night sky, AND free is just too much to ask of this internet. however, I was able to find all those bits, so they just need to be put together properly. attaching the resources, and a mspaint example of what needs to be done (probably going to make you cry, or laugh, or both).
[cant_texture.png expired]
[arrakisday.zip expired]
[starfield03.7z expired]

yeah, rotated it properly, repacked everything and uploaded, and we are done here. thanks again.