What a cool house design! Off the top of my head, I think I'd be inclined to paint the brick surrounding the sliding door (1st image) and either paint the pillars or clad them in same timber as the ceiling just inside that same sliding door (1st image). I'd be tempted to leave the large wall as bigreader suggested simply because it's such a magnificent feature. If you live with it for a while then still not loving it, then paint it. While I like the chandelier, it doesn't really suit where it is, as Warren pointed out. If you wanted to change, best to consider if there are any other electrical changes you want to make and get an electrician out only the once. As far as paint colour goes, do you know what the current wall paint colour is?I'd paint to match the wall colour and complement the carpet, but important to know if you like the current colour or want to change. Also it would help to know what your own plans for the interior style is. Do you want to remain true to the 80s with just a few tweaks, or change it completely? About the balustrade, do you want to change the colour of it as well? Is it also made out of glass (couldn't quite tell from photo)?

I don’t know whether you have done your painting or not but with your dark furniture and existing windows I would paint walls light warm grey and 150% strength same grey colour on the architrave .something different and grey , yellow and brown look good together.

Dulux whisper white. Get a sample pot, paint a large piece of cardboard and see for yourself.

Lovely turquoise sofas, and your lounge has lots of natural light. What is the current wall colour? If you placed your sofas along both long walls, this would leave the window wall free for your view. Then you could have art on the walls behind sofas, or create a gallery wall of framed family photographs. A circular timber coffee table, or nest of tables, might work better in this scenario, with added benefit of no sharp corners for your little one.