This is also an issue on the new 2.7.4 version apparently. Seems like this was intentional or they just aren't aware of it.
Originally posted by @TheSuperEpicGamer in #519 (comment)
2.7.1 sky would become fully dark when in a supercell. This does not appear to be the case anymore however.

2.7.2 and 2.7.4 sky looks considerably brighter:

Originally posted by @TheSuperEpicGamer in #519 (comment)
2.7.1 sky would become fully dark when in a supercell. This does not appear to be the case anymore however.
2.7.2 and 2.7.4 sky looks considerably brighter:
