Something like this may work. Note the changed door positions so that anyone in the bedrooms can visit the bathroom without disturbing anyone else in the lounge !

I think the yellow and grey might bring out the gold-ish-ness of the couch.. I'd try to go with more blue colors.. Maybe some navy pillows and a rug with the blue in it as well. The curtains, that ying-yang rug, and the lilac rug just gotta go.. They're dwarfing all the sophistication this room will be able to have with that tile floor and those big beautiful windows. I love the dining room chairs!

You can use natural stone like marble for floor but do not use granite for floor at all as it is very slippery when wet. As for tiles do not go for glazed vitrified tiles for the floor for the same reason. ( floor becomes slippery once wet and may cause mishap) Go for ceramic anti skid tiles that are specially meant for bathroom floor. For wall tiles you can use whatever you like and then decide over the matching anti skid floor tile/ marble. Double charged vitrified tiles are usually used for flooring in rest of the house.

The living room window itself does not appear to be designed to let much light through. Please show a photo of that window, also of what lies outside the window. In the meantime, I suggest that you replace the builder-installed window with one of your own choosing. Use toughened glass rather than this heavy grill. Minimise the frame, if possible, particularly if there will not be much air coming through. If there is the potential of air but not much view, then have a sliding or bifold window that maximises the opening. On the blank wall outside, if that's your view, put up a green wall, creeper, something to improve the outlook. For nighttime viewing, add mild uplights in a natural white shade, focused on the greenery. Or else, you may be able to put up a reflective surface on the facing wall, to bounce in more of whatever light there is. Such as a coloured glass mural if not a plain mirror. Once you have maximised your window, move on to the wall to the right of your living room photo. That is, the wall that your living room shares with the west bedroom. Use a very large mirror on that wall to expand your living room visually and to bounce more light around. To cut down on expense/effort you can make it out of several standard-size sheets rather than one giant sheet. However, if that wall is to be covered with storage, make sure the front surface of the cabinetry is fairly light-coloured and reflective. Last, if not yet satisfied, consult a lighting expert for this room. That would be useful. These are fairly expensive solutions, all in all, but they should help.