I actually think you are on the right track with your colour scheme of browns and blues - see the photo I've attached that has a 'spa and gold' colour theme (found on 'howtodecorate.com') your lamp would tie in with this colour theme, and your sofa is 'gold'. This colour scheme looks elegant but also relaxed and I think would suit the style of your house. Would you consider painting your wooden panelling a pale blue? This would add the weight to the lower half of the room that Sian mentioned and add subtle colour. From what I can tell from the photos, it should work with the wall colour, although the walls could possibly be a bit lighter. I would move the mirror to above the fireplace (I think perhaps it's too large where it is) and add some artworks to the walls (in gold frames). I agree that a coffee table would be good. I think the rug you already have will work if you just add some some cushions and throws in creams and blues to the sofa to tie it in. If you purchase an arm chair, I would suggest it should be a pale cream or coffee colour as per the picture. The tv unit does look quite dark, it might lighten the room if it was a paler colour - perhaps you could simply cover it with a material slipcover in a light brown fabric which would also hide the contents, that would look more elegant.

1. Delete current door location and have a full wall on the MPR/Entry side. Relocate the access to the MPR/Dining wall, but choose a flush cavity sliding door so that you don't loose any wall space (in the MPR) against which you can place furniture. The cavity door can be as wide as you want or even double cavity doors and flush ones will be completely inset in the walls when opened creating a seamless opening to main living area 2. MPR is 5.3 wide so big enough to create two zones: A. a lounge area with tv unit (built-in with plenty of storage if you can) against the garage wall, an L-shaped couch with the return/chaise part against the kitchen wall, one or two bean bags near the window wall and a large rug to frame it all B. second area would be a built-in desk (with extra storage and shelves if possible) along the full length of the entry wall, which is wide enough for two computer stations (don't forget your data points) and when the door is open you can see what they're up to from the kitchen ;) Good luck!

Your scheme is very Deco like, the cornice is I'am finding the window treatment too heavy perhaps change to a lighter colour of light beige or white as per photo Colour scheme at the moment is black white and silver it needs a bit of lightening up to add some warmth but I can see Ghost dining chairs really working in your dining room but I think you mentioned keeping the current furniture cheers

my suggestion reduces the width of the guest bathroom to a modest ensuite size (1500 wide) or very generous powder room with the extra width added to the study for a built in wardrobe with an 800 wide toilet alcove behind the door for privacy (door must be shut to use the toilet) and a full wardrobe for the study (i've included a queen bed and desk to illustrate the available space and the study and guest room are now interchangeable)...the shower is 1500 x 900, the vanity is 1500 x 500 and toilet depth needs to be less than 700 deep with a carefully positioned door stop to prevent the door banging into the toiletbtw consider making the tall laundry cabinet deeper and wider (ie 750mm) if it's to be used for vacuum cleaner, ironing boards, brooms etc and the counter for the sink also needs to be deeper to neatly enclose the dryer and washing machine with suitable air space all round and easier access for concealed, inside the laundry tub cabinet, taps for the washer and dryer