When you're outside of Ultimecia's throne room, you would notice a red star (sun), which appears to be pretty dark:
There's no dark cloud blocking the view of the Star ... and yet it's still dark.
Look, the other areas of the sky appear to be clouded, but not the area where the Star displays.
This proves that Square was trying to hint something.
When the camera brings you into the lower part of the room (approaching Ultimecia's chair), the general brightness goes up, and hence the star looks a bit brighter - Where did this extra brightness come from? The flames, gold religious stuff and the Lifestream on the ground.
This red star looks like it's dying. So that must be millions of years into the future, not in hundreds of years. In the present days (Squall and Co.), the star looked pretty heathly. Apparently, this star doesn't seem to be heathly.