Good room colors?

Hey! Im moving soon and I have the opportunity to paint my room for the first time which is exciting; although, I want to make sure I dont hate it in the future like I hear so many stories about(tho i could probably just repaint it)

I made a forum under "helping each other" and someone suggested a light blue-grey which I liked. This was before I found out I could do multiple colors tho.

I really want to paint it a fun color-maybe a cool shade of blue and/or pink or maybe a light green or maybe a light/pastel orange. I also like the way dark grey/black and dark red rooms look(and just dark rooms in general). I also kinda want to paint each wall a different color or have two walls be one color and the other two a diff color as I cant really do intricate patterns. Its also worth noting that there are two massive windows in my room and I want the light to be able to bounce around, so maybe not dark colors....idk. 

Also also, I have a bunch of posters/tapestries/shelves to hang up and the basic color scheme of my appliances(desk, bed, bookshelves etc) is grey, kinda brown, and white although I dont really care too much about those matching overall.

Im a teenager and would like feedback from people who've had their rooms painted for a while or anyone with a painted room in general! 

Thanks in advance! :D