Most hellebore flowers I have seen turn to green when they go to seed despite the original color. This is one reason that most flowers are photographed soon after opening...when the color is most vivid. I have seen some plants that keep the color longer than others, but the greenish color seems standard for older blooms. The green blooms on your niger were likely the same white/pink as the others several weeks ago.

Oh that is weird. :D Interesting I would love to know why they do that. Thanks so much for your help.

hello Alicia

This kind of color change intrigued me also , so I was looking for some explanation . I am not a specialist but as I observed my Hxhybridus I add to what Joseph says ( young flowers ) that we need the correct climatic conditions , this means the right day length and "correct" temperature.
Some of my whites flowered out of the season and were to some degree green . I think that this has to do with the photosynthesis that starts when day length is longer or temperature higher .
I like very much your why question , so I hope you permits me to give my personal view on hellebore colors .
Photosynthesis has to do with plastids , this is a general word for particles that are included in a cell ; Some of them carry genetic material but may not be confused with the chromosomes with genes following predictable Mendelian
laws.
To my opinion the genetic color range of hellebore is limited to Dark Rose and White and when not present Green remains .
The other colors , Yellow and Black , and spots are under plastid control .
If this is true then the motherplant is very important if you want to improve one of this colors , but this is also what local breeder do and told to me.

To become more information about the "greening"-effect I collected the seeds of my out of the season flowers and I hope that I can see the seedlings flower within two years and compare them with the normal white seedlings .

You may always send other why questions.

johan

Here is a link that might be useful: fynwerk

Hello Johan,
I have recently become interested in the relationship of environmental factors (such as temperature and photoperiod)to hellebore flower color. For example, plants may hold 'true' color longer when temperatures are cool. I also look forward to experimenting with this situation in the future.
Of course, genetics also plays a key role as some plants hold color better than others, and some seed pods and nectaries are 'colored' rather than green even in the seed stage.
I find your comments very interesting Johan.

Hello Joseph
I tried to send you a mail by the garden web facility :
but something got wrong I think .
If you are interrested sent me a sign of life on my homepage .

johan

great info thanks

hello all

May I come back to this color question ?
A year ago I got interested by the color of H x hybridus as I had done one test with a Hellebore of color Rose . By counting the colors of the seedlings of one selfed plant , it was possible to interpret the figures by comparing them with some genetic rules .
One thing was not clear to me , The Spots !
After one year , one test , nice conversations with ( hobby )- breeder and some correspondence ( USA , Germany , Holland , Belgium etc .) , I got convinced that some color - traits are not under normal genetic control .
So I got browsing for " Mendel and beyond " and found something about plastids with some colorful details .
Nowhere I could find a general model , only very analytical stuff.
Now I included a new page on my website " 2 HELLEBORE hybridus / spots and plastids " containing a compilation of some papers .
I did my best to write it for average gardeners as we all are in the garden .

Every interested reader can visit my homepage but is also kindly invited to give some critics .
It is of great interest that everybody who has figures about crosses is willing to share this information with me , this will enable me to refine the model .

johan

Here is a link that might be useful: fynwerk