White squares look great with white shirts. SF has a bizarre aversion to white shirts, but that's SF's issue. White squares can also look good when crispness is called for (as with suits) or when there's white elsewhere in the outfit, so that the square echoes another element.
Sportcoats with blue shirts and earthy colors, on the other hand, aren't demanding crispness, starkness or austerity. That's what led Foo to the cream square, which is a rather feeble compromise.