If you are seeking a truly open feel to the floor plan you have shared, then using one material in the mail living area is the best approach to making this space feel truly open. Using a variety of materials on flooring chops up the space and decreases the visual footprint. I would suggest using wood, tile, or if you are on a tight budget laminated flooring for the living/dining/kitchen. Then use carpet in the more intimate spaces; bedrooms and possibly hallway. Save the tile for the bathrooms.

We are a little biased, but wood floors are versatile, durable, clean, and timeless. Whereas carpet will eventually need to be replaced, high quality wood floors can last forever. You can install radiant heat under the wood floors if you are worried about them being too cold during certain times of year, and you can easily install area rugs over the flooring. Wood flooring is also more versatile than it has ever been so you can create any look. As an added bonus you can easily sweep and mop your wood floors, whereas with Carpet you don't always know what is lying below the surface. Good luck!

If it's brand new, have you tried asking the supplier what they recommend? We got a booklet from our supplier when we got new carpet with ways to treat various stains on that particular carpet. Each kind of carpet will be different. Also, have you tried a professional carpet cleaner? If all else fails, try your luck with your insurance company - I know others who have got carpet replaced because of bad stains - depends on your policy.

I was about to say grey until I read the last line. What about a light brown carpet?