Name: Marilyn, aka "Poly" South San Francisco Bay Area (Zone 9b) "The mountains are calling..."
I recall reading somewhere (probably here on ATP?) the comment that the near-white dips are whiter than the near-white tets, with the speculation that maybe the greater thickness of the tet flower tissue (more underlying yellow) was the cause.
Among my tet near-whites, I think that 'Voila Francois' and 'Winter Wedding' are maybe the whitest, but some of the dip near-whites (that I have) are maybe a bit whiter than that...