Please keep in mind that I am totally clueless, I only found your question interesting and played around a bit in the editor.
So… my answer might be not a good answer at all.
If this is what you wanted, I just created a new level of type “Basic”, then selected the SkyAtmosphere and changed the Rayleight Scattering. Not because I have so much knowledge, but because the color behind it seemed to look like the current sky 