Green usually goes great with gray. Jewel tones do too. Burgandy, purples, blues - try holding some of your clothing or towels, etc. against the wall to see what appeals to you.

I like pops of yellow with Gray. What kind of bedding do you have? Any pictures?

Layer shades of white create texture with it, such as adding burlap to the curtains and making the beading have multiple pillows and a fluffy comforter or use a quilted flat with color in the sheets and pillows. the brown tone of the burlap will warm it up wile keeping it crisp with the whites.

Sorry my room is messy.....not done...was just deciding on the decor, so posted this pick to ask for advise from experts, few designers said that yellow looks great with greys. Hope this helps... Gppd luck

Grey tones look nice with a touch of faded red and or a light toupe