How to read the map?

Hi, i understand the rectangles next to solar systems indicate the n. of planets. If they are empty you don't own them, if full you own a planet. Correct? Do they also give an indication if they are owned by somebody else?
How can I understand if they are free other than having ships in orbit?

If the little rectangles are blank, then nobody owns them. I don't know off the top of my head what the two colours are for if you own them and if someone else owns them.

Really wish enemies and allies had different colours. The map is really ad to read now

There are 3 different types of rectangless from the "sector?" view. Orange outline but empty means no one ones them, orange solid means you own them and Dark purple means someone else owns them.
What we really could use is some indication to tell us if we are looking at an outpost or a colony with population... wasted several of my fleets on ice planets people decided to colonize... not cool.