Agree with carrieandjimh, You will need to connect the two colors through prints on pillows, curtains, rug etc. Can you post a pic of the sofa and wall color so we can see what we're talking about here? Thx.

Your floor and other wall colours are great but Red (orange), black and white are very harsh together, the wall cabinets either side of the range hood have been badly installed, they should have been built to the ceiling. My suggestion is because the kitchen is small, I would remove the cabinets either side of the range hood and then run a row of white cabinets across above the sink to the end of the bench top. Paint the walls white or a soft grey, the range then becomes a stand alone feature. You didn't mention what the splash back material is but I would consider a clear mirror splash back along behind the sink and up to the base of the new white cabinets so that you're not just looking at a wall. cheers

As said by big reader...leave white or paint the same colour, without the brushed finish, on the other walls. You can not bring another colour in. There is enough colour already with the orange wood and the bed cover. Also, the curtains look too small to pull right across your window correctly. They should be waved not flat when closed.

I agree with Jan -- a lot is personal , and your lifestyles . You say neutral colours , so a wheat type colour for the carpet is a good middle of the road choice , but maybe not practical with kids who like crayons and facepainting and stripping down motorbikes haha . So in that case , maybe a burgundy or mid blue or similar 'solid' colour may suit better ( burgundy may tie in more with the exterior tones ) , but is still sort of neutral , but what about furniture and linen and artwork -- if you have royal blue or fluro green drawers and a brown chair and sunshine yellow duvet/dooner cover , and the room is for someone older than 4 , then burgundy carpet mightn't be the go haha . The existing wall colour works with most things , you can add artwork or posters or sports or academic certificates -- maybe back to front , but I'd sort out everything else ( carpet , furniture , etc ) before deciding on a wall colour , unless sticking to the existing or similar colour .