Change a dimension's sky

So my old world got corrupted and I had no backup. I figured it was time to change some mods and start a new world.

I didn't want to go through the early game again and figured I'd build a base in a void dimension in creative with some basic mid/late game infrastructure and go from there.

So I went to the last millenium and started building out of basalt and Sky Stone. I did not consider the fact that, there being no sky, a black building over a black background looks awful.

I don't want to start building everything again and trying to copy it would be a lot of trouble.

Tl;dr: Can I change the Last Millenium's (or any other random dimension's) sky?