I guess there are several ways to deal with that. Paint it the yellow of the wall to help it disappear. Alterntively, have fun with it and let it stand out. Or you could really be creative, such as painting it with climbing vines and flowers.

Cute desk space, I love the yellow and white, and the flowers. I'd hide only the pipe that's on the desk itself -- construct a long, narrow 3-sided box, paint it white or yellow, and stand it on edge to conceal the pipe. Keep the niche for the flowers. Use the box for sticky notes.

Following up on the ivy idea. First I would paint the pipe to match the wall. Craft stores like JoAnn sell fabric ivy or grape leaf vines that you could glue or tape to the pipe.  Spiral it all the way up.

Duplicate posts are a PITA

I forgot to mention the heat pipe has insulation wrapped around it. I know you're not supposed to do this but the previous owners did it

I don't know anything about this company and maybe there are others, but I think this could work:

I would find a stack of shelves, baskets or boxes to fit between it and the wall. When they're full of colorful items, the eye won't notice the pipe so much. It seems well hidden on other shelves.