The range of colours is almost infinite as they vary in intensity as well as shade and the colour may vary across the sepal. The main pigments found in the hellebore family are anthocyanins which give purples, chlorophyll which gives green and flavenoids which give yellow. There is no true red pigment so all red hellebores are a form of purple but some are less blue and give a good approximation of red. A wild H. atrorubens I have has the best “red” that I’ve seen.
Black is a very intense purple that absorbs so much light it seems near black.
In addition to the pigments many flowers (probably with genes from H. Purpurascens) show a waxy bloom that creates a new shade. These are called “slaty” as they give the misty sheen of slate over the background colour.
Flower colours
White - the hardest colour to achieve in pure form without spots or some green sepals
Red - our best red so far, also red nectaries
Pastel blush - red nectaries
Pink
Jade green
Yellow golden yellow nectaries
\Primrose - red star centre and nectaries
Peach
Apricot
Red and green bicolour with red picotee
Black
Slaty red
Slaty grey with light spotting
