What colour should I paint my sons walls? When...

[Squigwords]

He has a mid grey carpet.
Grey and white wooden furniture.

And he has this rug? (I know it's a but weird to have a rug on a carpet but he loves soft things and lays on it all the time!)

He's 13 and I'm surprising him with a room make over. I'm getting him a new bed (he doesn't want his high sleeper anymore)

So I need a wall colour, curtain, bedding colour.

I don't know if having the walls the same colour as the rug would be too feminine?

https://www.ikea.com/gb/en/p/malm-bed-frame-high-w-2-storage-boxes-white-luroey-s99011504/

i would get something like this if
you already have white furniture. It’s less than £200 and includes storage drawers

At 13 I would get him a small double rather than a single bed.

As for the walls I would go fairly neutral, say a very light grey, and then one wall a statement wall in something like a deep red or navy or if dark isn't the way you want to go then maybe sage?

What's he into gaming Minecraft etc. Grey goes with just about anything. So you could use grey for the base colour and get some big wall stickers. Or have 1 feature wall.