I like the concrete bloc walls. They are becoming quite fashionable today. I'd keep them in the natural concrete color or if they have been painted, a color paint that resembles concrete. The concrete walls give a hard and cold impression so I'd choose wood flooring for the floors. The combination of a warm wood on the floor and hard, cold concrete on the walls is a nice one. Brighten the space with colorful modern art.

Absolutely no problem changing up the carpet. Things to watch for......make the transition in a doorway, an opening or along a visual break in the rooms (like the corners of the walls). I would stay in the same colour range, but just go to the other end of the spectrum rather than change the colour completely.....like light grey going to dark grey, not light grey going to navy blue. You want the separation but an easy transition on the eyes.

Love blue tiles. Depending on how much sun and how hot your pool gets in the summer should dictate what color it is. We live in Arizona, so cool blues work best. Our neighbor has brown tile and a dark pebble tech pool. Looks like a swimming hole and gets really hot - 94% water in the summer. They obviously didn't think it through.

For this look, I think you'd need 1/3 plain tiles but I love this look! I've never seen it before and it's very intriguing.