Thoughts about sphere worlds

[Kamog]

It seems that there is only one picture for a sphere world, and it's a dark grey color regardless of the atmosphere type. I thought that it would be nice to have a blue sphere world for an oxygen atmosphere, red for hydrogen, and so on, just like the planets.

But I guess that the atmosphere is on the interior of the sphere and not on the outside, so the inside surface will have different colors, whereas the outside has no atmosphere and has the same appearance as a "none" planet..

So the facilities and population live on the inside surface of the sphere world, and they get sunlight from the star in the center, right? Now, I'm assuming that the sphere rotates around to create artificial gravity so that everyone stays on the ground and doesn't fall down into the star in the middle. But with a rotating sphere, the artificial gravity will be strongest at the equator and get weaker as you go towards the poles, and at the poles there won't be any gravity. So if you live on the equator, and experience 1G of gravity, you start walking north. As you progress north, you will get lighter and lighter, and then become weightless, and then the direction of the gravity will reverse, so that you fall towards the star.

Does this make sense, or am I missing something?