I changed mine to its current beige Milky Way back when 2.2 went live and wrecked the galaxy. Before that it had been the same thing since before 1.0.
Once 3.0 goes live I'll change it to something more appropriate, lol, and that's how it will stay for years most likely.
Forum or in game?
Never to both, but just curious to which you are asking about.
I change mine quite regularly depending on conditions and if I need to hide from Brett when he's in a let's troll T.j mood....
My current one is part of the Photoshop I did last week.
https://i.imgur.com/o3hQO40.jpg