Nramsey - more of a turquoise or teal color. Just not really my favorite or typical style. Was thinking a darker gray?

I would definitely paint the accent wall to the grey of the other walls. I think accent walls can still be used in bedrooms and possibly a theater but for most designs it looks dated. I love the grey they chose especially with the flooring, it will easily act as a neutral. Grey works very well with patterns and pops of color. Check out the ottomans here if that pattern was on two accent chairs with a white sofa it would look awesome! This is a dark version of the design, I'm drawn more towards the lighter tones, but this gives some good ideas for the fireplace and then maybe use white or vintage wood for the shelves instead of black. One of the first things I'd do is find art you love for your walls. The art will help you select the color palette for the room. Whether you go with cool colors (blue, green, purple) or warmer tones (red, orange, yellow). Accent the paintings with a directional trim on the recessed fixtures you already have in place. I would just switch the bulbs to an LED MR16 bulb so the light doesn't hurt the painting http://www.affordablequalitylighting.com/lightbulbs/led-light-bulbs/led-mr16/12v-10w-vivid-color-cri-95-led-mr16-spotlight-soraa-light-bulb/ The LA museum is switching over to these to protect their art so you know they are a good quality

Add teal. Teal. Teal. Grey and teal are very modern.

Pair the grey with yellow.

Thanks everyone! Any suggestions on couch/chairs?

love the grey, I would change the teal/blue to a 'muted' orange-red. If the couch & chair are in good shape buy them, get some orange & grey throw pillows for accent ...
...good luck

The fireplace has the teal in the tile surround, which is probably why they went with it on a wall, but that color is pretty intense, I like the suggestion of bring all the walls into match and then you could use the teal as 'pops' of color in pillows, accents and rugs you can change out. It's a lovely house!

First of all congratulations on your new home! I just refaced two fireplaces recently and so my vote is to definitely add a stacked stone to the ceiling. It adds warmth, dimension and texture to a room.
Then pull a color from your stone for your accent wall. I think you could do a larger rug to ground an L-shape sofa. Do a rug the same size as the one in the photo, over by the chairs to create another conversation area there. Lightly patterned window treatments and you'll be feeling at home in no time.
Enjoy the process!