Dany your english is very good!
I'm not familiar enough with what daylilies are available in Europe to help you with your black program, but I can give you a few links to try for European growers/sellers.
In this first one, in the box on the left go down to "Links". If you click on the European Daylily Links it will give you a list of growers with links to their websites.
http://www.hemerocallis-europa...
This link will take you to Francois Verheart 's website which has an on-line catalog. Francois may be able to help you.
http://www.eurocallis.com/
Both of these can be found on Francois's website.
Victorian Gardens Star Bright, popular here. This link is to our ATP database page.
Daylily (Hemerocallis 'Victorian Garden Star Bright')
Rolling Raven is a 10 1/4 inch black spider. This link is to our ATP database page.
Daylily (Hemerocallis 'Rolling Raven')
When you said a small, dark daylily the first one that came to mind was Little Donny Darko. I don't know if it is available in Europe.
Daylily (Hemerocallis 'Little Donny Darko')