Name: Suzanne/Sue Sebastopol, CA (Zone 9a) Sunset Zone 15
Moved to the Daylily forum, please start all your daylily questions here.
I just did a search in this forum using the word 'white' and several threads popped up.
As far as tetraploid daylilies go, the only one that is really white is: White Crinoline
Snow On The Mountain and Spacecoast White Christmas open with some color (pinkish), but turn pretty white by midday.
White Crinoline
Snow On The Mountain
Spacecoast White Christmas