Using the dimensions.json config below, I would expect my sky to have no moon/stars and a purple background/haze. What's I'm seeing is the moon and stars and a black background.

https://pastebin.com/qDSL5nNq

You have at least a trailing comma on line 91, which would break parsing the config.

Removed the comma, but same issue. It's possible some other Mod is over-writing the sky, Astral Sorcery and Thaumcraft Could be the culprits. But I specifically disabled AS in this dimension.

Enable the verbose logging option, and look in the console for any warnings or errors. Also try the /jed list-registered-dimensions command to see if all the dims are there and with the correct WorldProviders, and then run /jed debug while you are in the dimension in question, and check the output for anything relevant not being properly set to the expected values.

I added a new JED option SkyLightBlend to define the blend ratio of the sky color with the light level. The horizon/fog still looks a bit funny at night, but it's still quite good compared to the old complete blackness.

Blend ratio 1.0 (old behavior):

Blend ratio 0.0 during day, with the fog color set to the same color as the sky (30F0F0):

Blend ratio 0.0 during night:

That looks great, I'm sure I can fiddle with the sky/fog color to get the right level of creepiness I'm looking for. Plus now that I can set night, Dynamic Sound gives me all the night ambiance... Sweet.

debug did the trick. Turns out I am a complete idiot and forgot that I reverted back to 1.5.5 to test something and forget about the config changes, swiching back to beta-1.6.0 fixed the hiding of the stars/moon/sun.

The colors were not appear because I had set the time to 18000 because I wanted a low light level (day/night cycle is off). But I guess if you set the time to night, you get black all the time. I would have liked to have the color override the night sky (maybe darkened though) rather than force night to be black, but this may be intended behavior.

I will close this now, but let me know if there a way to change the night sky colors.