Blue or gray slate that compliments the stone in the fireplace (assuming the stone on the fireplace will remain). Slate flooring is a great way to create a 'rustic' feel without adding more wood.

The fireplace will remain and is the "centerpiece" of our living area. We recently sold our 4K sq. ft. home and now live here in our 1600' sq. ft. slice of heaven. The kitchen remodel was a must because I love to cook but felt so claustrophobic in the tiny galley kitchen. Love the open space. Thank you for your input.

I was going to say the gray slate as well. Get the rustic tile in the 18X18 and maybe lay it on the diagonal.