The photo below is my suggestion for colour of floor. Furniture should be darker - similar to below. For the rug - choose one colour from the artwork and find a similar coloured rug. Don't put a mantle over the fireplace - it could be a health hazard - bumps and bruises. Blinds - unless you want them to make a statement I think white - to match window frames would be fine.

How funny. I just renovated (on a budget) my small kitchen and added exactly the slate look in tiles you have, though they are in fact porcelain. And I placed them throughout the house for continuity. The tiler asked if I was after a retro hippy look but it doesn't look like that at all. My cupboards were the same colour as yours and I utilised the bones of the kitchen and had the doors and Benchtops changed only. I also have plenty of light in the kitchen but chose white doors and as I was on a budget I chose granite look Benchtops, they are very serviceable and it looks great. The blue backsplash was the colour lift and here you could choose any colour to your liking. Basically the kitchen ended up with white cupboards and appliances other than cooktop, with the stainless cooktop and coloured splash back being the focal point. The paint colour are: whisper white walls, integra splashback, white ceiling and for increased contrast I used the same white above the splashback on the rear wall. I would consider painting out the brick but leaving the texture.

I would vote for the top example here. Itr gives an earthy tone to the room and yet is still bright and wont show every piece of dust or food.

Hi there we went with a glass splashback in Haynes Minimalist #1. I can DM photo if you like? Learning for me is that the colour sample tile does not take into account a finished room, flooring, lighting, natural light etc. as glass is so reflective. I found it very difficult to find a glass colour that suited both the stone and cabinet. Cheers