I would actually start with looking for chairs or upholstery fabric that you really love, and pull your wall color from that.

Thank you for your input, i looked for chairs , very modern ones and i could go black , white or red leather but it's hard to decide because i have a lot of empty space and the stone wall with mirrors is throwing off my modern desired look, and i already have another living room with sofas etc, can only fill up this one and give it some texture and feel with armchairs and a small table... i think !! so that's why i need to figure out the wall color

What color do you like most? Any color, not just black, white or red. It's your room, and you should love everything in it! Maybe look at upholstery fabrics and see if any of the patterns catch your eye.

If you want solid colored chairs, what about a rug with some pattern to it, to bring in more colors? You could treat those mirrors like windows... Put drapes or blinds on them to soften the edges and make your room more cozy. Window treatments are an easy way to add texture and color. Drapes will also reduce noise levels, since you have a lot of hard surfaces.

If you want to fill up the room with something other than furniture, look for very large potted plants, possibly even trees, like the one in your dining room.