In "When it Rains" it can be assumed that Peridot has never seen rain. Most planet's have an atmosphere and they rain acid but still it rains. On stars, it doesn't rain because of the lack of atmosphere. So Homeworld must be a star. It's also been shown to be a star because of the Warp pad positioning and Garnet looking up at it when she was stargazing.
So now that that's covered, on to the real theory.
As you can see, White's holding a small white orb, I believe that orb is the moon. I think that White conquered moons and led gem courts on moons of not just our planet but all others as well. That would explain why Pearl knew about the moon base but the other gems didn't. Not even Sapphire, inside of Garnet, knew about it.
Yellow's holding orbs that shine like stars. I believe that Yellow led courts on stars and that's why she leads on the Homeworld star.
Blue's holding many bigger orbs that I believe are planets. Blue was coming from space to conquer another planet for a gem colony so I believe that helps support this theory.
VOUS LISEZ
Steven Universe Theories (Continued)
RandomThis goes along with my previous theories! I hit the limit on the other book.