Choose a colour from the wallpaper. If the room is smallish, I'd probably choose one of the lighter colours. But, done properly, a darker colour can make a small room feel cozy.

I'm not a fan of grey with yellow at all. I know some people love it though, so I'll say no more.

Thank you Jennifer. Yeah, that is a good idea to pick one of the lighter colors in there.

With Eternal Grey I would paint nearly as dark as the darkest grey in
the paper. Add in some softer yellow accents (prints and solid) and
along with your furniture,the room would be sophisticated yet still
restful. Have you picked out the bedding? I'd likely choose a solid but
textured ( linen,velvet,matelasse) grey lighter in shade for the bedding
and drapes. With a yellow/grey print throw. It is easier to find the
bedding and drapes first,paint last.

Thank you for @hollybar your suggestion. If i go darker color on other walls, should I use lighter shaded drapes contrast to wall color? I did not decide on bedding yet.. I was thinking to choose paint first..so you suggest to check bedding and drapes first?

It is much easier to choose paint last because there are an infinite number of paint colours,but not so with bedding and drapes. Also, the bed 'top', because it is so large & prominent, sets the tone and mood for the rest of the room. Usually more so than the wallpaper! How much contrast you want between the walls and the drapes is really a personal choice but a drape close in tone to the walls will make the overall space feel larger and more seamless.