Hi, I'd stick with a grey sofa, as you really like your white, chrome, greys. Not everyone likes bright colours and that's fine. I've put some things together for you, California Cloudy seems to work with your floor and isn't too dark or too light, I think. On your other post, about the art, I've suggested a mural for the dining room wall, and I've put one that I think looks pretty fab in this moodboard, but who knows... you might hate it :-) You've chosen cool colours, straight shapes and hard materials so far. Bringing in some softness (fabric), natural materials (wood, plants) and round shapes will make it cosier.

I see no issue in buying an ex-display piece. The green colour looks much better in the photo than I was expecting! I also see no issue with having 2x sofas in the same style but different colours. I’d go with the second sofa in a pale grey. I’d then get neutral scatter cushions to sit on both sofas and bring in some plants to complement the green. Couple of images showing two different colour sofas works fine...

It’s very comfortable to sit on. We got the matching pouffe too which can easily be moved around to use it either as a corner sofa or move it in the middle as a table. It’s easy to clean especially if you have kids. The number of times we spilt liquids on it. Super easy to clean with furniture wipes and ages very well. If we bought another sofa I think we would have regretted it. I hope this helps :)

You could go full jewel colours so maybe an emerald green but it’s a bold look and not for everyone. Or a nice gentle grey either very pale like the picture below and a more definite tone. That way you can bring the look together with cushions and a rug.