I do not have any tiles in my current house but if you think about grout discolouring and looking bad.... then I think that might answer your question. My thought - the less grout the better.

Hi there! I'm an Asbestos Assessor by trade and come across these a lot. In the UK these would be highly friable asbestos insulating boards, but here in NZ it's always pinex. No asbestos in these ceiling tiles :-)

Hi there. If the tile you have has character, you could pull a colour from some of that character, for example if the tile had a beige fleck through out you could use a similar beige tile in the bedroom, otherwise just choose something that compliments the tile well to create a soft transition. Then use the colour of the existing tile in the room somewhere, with your bed linen for example or bedside lamp. Feel free to share an image of the existing tile.

This is the only photo. Wall colour is white and joinery is black. The floor tile is the light colour and will be in the entry, kitchen, family and dinning areas as well as bathrooms laundry and toilet. Can I pull off the dark carpet or should I choose a lighter shade to compliment the tile?