I work as a colourist and the easiest method for a upmarket look is to choose an exact colour to match one of the colours in the tile. I would take the tile to a paint shop and get the colourist it match exactly one of the greys in the tile. Make the depth of the colour a light version. All white walls are on the way out. Lappatto tiles usually have some texture as they are semi polished. This is the latest look in tiles as they give a shine without the maintenance of polished porcelain which had been in. They are usually less slippery than satin or polished tiles depending on the brand.

What natural light do you get in the room/what orientation? i.e. is it a 'cold' or 'warm' room? If it's a colder room, I'd go with a grey with orange/red undertones to warm it up a bit, or if it's a warm room you could get away with a cooler grey, maybe green undertones to compliment the maroon. Or you could even try a green rather than grey. The Aerobus is a blueish grey so will be cooler. As others have said you would probably want a lighter tone than this for the walls (unless you're purposely going for a dark dramatic mood). 'Miller Mood' is a couple of shades up in the Colour Atlas. Get sample pots and paint a section on each wall, or paint a white bit of card and stick to the wall to see how the light is at different times of day.

Warm white or greys would work well for walls. https://www.dulux.com.au/colour/whites-and-neutrals/most-loved?gclid=EAIaIQobChMIwbzrqZaM2wIVzTUrCh0ALAneEAAYASAAEgLvKvD_BwE&cid=ppc%7Cgoogle%7Cdulux.com.au_main%7C%7CSpring_Oct_2017%7C%7C%7C%7C%7C%7C%7C%7CBrand+-+Colour+-+Specific%7C%7C%7CBrand+-+Colour+Whites+-+EM%7C&s_kwcid=AL!4713!3!266934234389!e!!g!!dulux%20warm%20white&ef_id=Wv0opwAABZ8L@CUB:20180517070055:s

Just be aware that the purer the white the more colour will be reflected off the floor. Your timber floor has some strong reddish tones, so any pure white walls will pick up a slight pink tinge as the red colour will be reflected off the floor, especially with any direct sunlight bouncing off the floor. Sample pots are the way to go, or steer away from the purer whites and go to warmer off-whites and beiges where the pink tinge will be less noticeable (but still there), Best of luck, Dr Retro of Dr Retro House Calls and Dr Retro Virtual Visits.