Which White?

Since purchasing my blue mosaic wall tiles, I've known that I want the walls of my new kitchen to be white so that the bold color of the tiles stands front and center.

Now the only question is which white? There are so many whites to choose from and what's even more confusing is how they change in different light.

While pondering my white paint chart inside I decided to take it outside into natural light. Whoa! Suddenly all the colors changed. Inside I preferred "soft white" but outside it looked too peachy and I leaned more toward the slight grey-toned "light fog."
  
I've got a few more hours to think before I need to head to the paint store and make a final choice.