For the fireplace inserts go ahead and do the green order a second set of panels that you store that are more neutral. In 10 years or five years you may not like the green anymore. It's possible you won't have access to different colored panels at that time. As for the color I like the ideas of going into those silvers it would coordinate very well with your blue couch and it will pull the blues out of the curtain panels. For the wall coloring use the warm golden color in the drape. There is one piece of the flower that has this color and it will balance the weight of a dark couch. If your room is small don't go too dark in this color. You could use it on the main wall and pick two shades lighter on the other three walls.

I have western red cedar shutters and I went dulux antique white. Painted on the wall and ceiling.

It looks like you have wallpaper on the wall behind the sofa. am I right? How many walls are you painting? Post more pictures of the space if you can. My inclination would be to go deeper like BM normandy, black pepper, taos taupe, iron mountain… but hard to say with seeing so little of the actual space.

Textured linen or with a subtle print wont date. Feature walls make a room smaller as they jump out ar you. Wouldnt recommend. Get some interesting art or craft. Pick up colour with accesories