1. The numbers are in chronological order and that's all I'll say.
2. If you're guessing the colors, they're incorrect. It'll be obvious when you find them. Like I said through, this one is probably the hardest to find.. It possibly could never be found.. but there is a hidden hint to help you find it in game, which I'm sure many people have stumbled upon but don't quite understand the meaning.
3. Constellations have nothing to do with the button.