If you got the latest AHS daylily journal (vol.68 No.4 . winter 2013) you probably read the article OUT OF BLUE. This article has several hybridizers explaining their approach toward the blue daylily or so called blue daylily.
I don't have much experience working with blue daylilies, but here are a few good ideas that I pulled from the article.
Sandy Holmes - Has observed that blue most often appears when she crosses smoky grey watermarks with dark eyed or patterned eyed daylilies. Moldovan told her that the greener the throat , the better the chance of blue.
Ludlow Lambertson - His first thoughts of bringing blue to the surface were by using a white canvas to clarify the colors.
Now that I have a few good ideas I know which way to jump. The rest is trial and error.
I think most people are crossing blue with blue or crossing pattern with pattern ; in hopes that they will get something good. You got to think outside of the box and create your own.
Some of the blue daylilies from Florida are not so blue when you bring them north and the white backgrounds usually looks yellow. Some pictures don't always depict the true colour or average bloom. So do your homework and you will be off to a good start.
If anyone is working toward blue share your experience.