Not many, and 'Y' would that be...?
Yellow Bouquet
Yellow Bouquet is another one which has put out polys every single year it's been in the gardens, I should find some pics and upload them.
Last year, Ron & I took a several hour drive out to an AHS daylily garden (made an appt. in advance), and told him ... 'one thing I DON'T need is any more yellows!'
Came home with 27 new daylilies ... and six were yellows or yellow-blends that did not come close to anything else in the gardens.