Well, the problem is this. I traded planets with my friend, and aparrently the planet turns red? But the fleet is still green. Zooming out, I noticed the system turned from a green white to all red.
At the moment this happens even if you don’t trade a planet. e.g. you enter orbit of a planet of a friendly player and the labels are green, you leave orbit and they turn red instead of staying green. It should be fixed soon, thanks for posting.