If you mount the tv I think you'd need a unit that runs nearly the full length of the wall, the current one looks a little too small.
I quite like the rug & feature wall together but the rug does look a little small for the space.

Otherwise if you are wanting to change the colour of the wall then grab a larger rug to co-ordinate with it.

It's a bit hard to suggest colours, can you advise your style preference & whether you were wanting to paint the whole room?
Are the side walls a pale green?

Also could you add a picture from the perspective of the lounge or a room sketch so we can see the shape /space you have available to place the seating in.

Your 'bones' are good from what I can see though :)

Mount the tv on the wall if you want and then paint inside the shelves black and keep the outside of the shelf white

Also get a white table with white cushions

This seems like a nice room Do you really want the main feature of room to be tv