I agree with the other comments, wait until you white wash, but I would be tempted to paint some colour of the walls if you cannot remove the trim (it might be there to tidy up the joins).

Levarne Sobotker....although the tiles are beautiful you are very brave having those very glossy tiles throughout your whole house...from experience of having glossy tiles - they show every mark and really need cleaning multiple times a week - and you can't just mop very glossy tiles because the water marks show when they dry on - so you have to do small areas at a time and dry as you go - it will take an age to clean them if you have them through a whole house. We have gloss tiles in a couple of bathrooms and I would never choose them again. They are also very slippery when wet.

I would have a look at Colorbond Surfmist as it is an off-white with a cool blue/grey undertone that will work well with Basalt as will as the existing stone. I wouldn't consider a pure white as it would be too contrasting. Best of luck, Dr Retro of Dr Retro House Calls

I have shadow line ceilings, mine are simple and inserted guessing mdf. The designer wanted to create more shadow lines. Keep it plain and simple. Also my ceiling, walls and skirts are all painted in Whisper white, ceiling in flat, walls Saturn and skirts in semi gloss. This was the designers idea, saying that pencil line ceilings always should be done like this.