I love the colors you have now. The cool tones ot the gray rug bring out the warm wood tones in the coffee table and floors. It makes the sofa fabric look like rich linen. So stay in that color range for the new rug.

Bring in warm and cool gray pillows and decor as you have done. Mixing neutral grays and browns and creams is trending now and you're on the right track.

A gallery wall or set of paintings of bold art in your colors. You could add your current map art to something like this. Grays and browns yet nice and bright art for that corner.