That's interesting that you're seeing the fixtures as off-white....I've found the fixtures to be brighter white and the tile to be more creamy.
Here are all my whites together. The subway tile is Daltile "White", which is creamier than both "Arctic White" or "Kohler White". I had some concern about the mismatch, but I like the look in my old house. Tub is Kohler Archer and toilet is Toto in Cotton. I realize it may not be super-helpful since you're looking for modern, and my aesthetic is more vintage. I'm just surprised by how different the color looks in that pic of the Kohler Villager tub!
Q
12 by 12 bath tiles cut to 6 by 12
Q