You know what, I would move in, place your current furniture and live with it for a bit, then you will have a better idea. We jumped the gun on a couple of rooms in our current home which we moved into 4 years ago, and I wish I'd waited a little bit to get how we use the room, etc. That triangular area doesn't have to have anything on it...it could stand alone as just an architectural detail. We have some of those in our living room, & I've put nothing on them & it looks fine....depends on if you feel the need to decorate up there. I agree with Shannon that I'd put an additional chair, if you use one, on the side opposite the window to balance that area or if that piece housing their tv isn't staying, you could put your longer sofa along that wall, thus opening up the beautiful bay like window & put the chair on that side for reading. Where are you putting your tv...is the large piece staying? You could put your tv above the FP, maybe. If you have wood blinds, you don't really need drapes, unless you want the softness of fabric. I would leave that decision for a bit. Christopher Lowell (from hgtv, etc.) has a book on the seven layers of design & he advises window treatments, accessories, etc. as probably the last step. It is a beautiful room, BTW, and I hope you'll post as you decorate it!! Good luck!

I would not add blue to this room. The orange looks great, and suits the woodwork very well. The wall looks, to me, like it has some olive green tones in it. Green is the complementary color to orange, so that's why the walls and sofa look good, and go well with the rug which has both those colors. Blue would be jarring. The rug is a bit too small since the furniture does not touch it. I would face the sofa towards the fireplace with the rug in front of the sofa, with the sofa feet touching the rug. The gold chairs could go on either side of the sofa in a C shape, or remain side by side in an L shape conversation area. I'd put the orange pillows back on the sofa, and get new pillows for the gold chairs, in a solid green color taken from the rug. Consider a similar color for the drapes. I wouldn't put art over the fireplace, and definitely not a mirror since it wouldn't reflect anything interesting. Stick with sculptural items, maybe a bit bigger than the items you have now. Hang a piece of art work over each of those lovely bookshelves, a little lower than you currently have the one painting. Or even prop it on top. But don't put other things (vase, clock) on top of them. Too fussy and distracts from the woodwork. 2 desks is one too many in the room. Keep a desk on the wall where the guitar is, and leave the other wall free of furniture, as a walkway. Your white front door is a bit too bright, and doesn't look good with your woodwork. Paint it a green color, not too pale, that looks good with your pillows, rug and wall.

Repose walls and white cabinets will look great. So will the espresso. That is very dark brown, like coffee, right? I love picture frames that are simple flat panel espresso colored/stained wood where you can see the wood grain but they look like wonderful dark coffee and they are a good two inches wide on a big poster. (Yikes, I always see things in terms of food, granite counters look like vanilla fudge, or jamoca almond fudge ice cream, or nougat candy. I really couldn't do that, I'd be running to the store all the time!) There is a frequent commenter here, Anglophilia who used I think repose grey on her walls and white on her cabinets, or was it white on her walls and repose grey on her cabinets? I can't remember! Why not invite her on this thread and ask her. She used Corian white countertops and Carrara marble backsplash and her kitchen looks just wonderful. https://www.houzz.com/discussions/4779243/finally-my-kitchen-reveal-work-completed-in-aug-2016

WAIT and plan to redo the entire fireplace wall. The hearth is too high, the surround too short, and TV should be somewhere else. There are lots of ways to improve the overall vignette here, but they will be pricey. For now, you need 1/3 hardcover books that you can even pick up second hand. They can stand, lean, or stack lying down to support some other decor. The decor items should be large enough to be seen and identified from the seating. If you want more interest, wallpaper or paint custom cut pieces of luan or foam core to slip into the back of each shelf.