I've seen a lot of clawfoot tubs with subway tile accent wall(s). Some clawfoot tubs are painted black. Maybe the grey tile floor, white subway tile, black outside the tub? too much tile? too much white?
Erika @ Urban Grace Interiors uses a simple, clean subway tile, but also uses a decorative border at the top. Via decorpad. I'm a fan of contrasting the crisp whiteness of the subway tile with a pretty paint color on the wall.