The lack of papillae just means it isn't Nymph. According to the description in the register it should have a "pale yellow green diamond shaped flare with a slightly feathered margin of deep purplish pink" in the central basal two fifths of the tepals.
We have seen a lot differences in the intensity of color depending on mainly temperature (it seems), but there might be other factors (soil, pH?).
Here is a photo I found, supposedly Bonbini, that shows it in different stages of bloom. Age of bloom definitely makes a difference as the color fades before the flower wilts away. Enlarge the image that has a bunch of blooms, on the right:
http://lilyflowerstore.com/CSS...
My Bonbini wasn't nearly as spectacular this year as it was a couple of years ago when it first bloomed. It was more like Bomb-bini but I'm not going to complain too much since it was a no-show last year.
