These guys were two dark eb males that were part of my old breeding herd. The second one from Kessler was almost an xdark. He is a little red in the hip (result of being 13 years old and exposed to a lot of sunlight, this is very undesirable in ebs, he had stopped breeding at that age) The first one is from Somavia.
I tend to see people label their ebs darker then they really are.
The first pic in rcr's post labeled as a tov ebony doesn't appear to be a tov eb. I see no evidence of the black mutant gene being present. The area around the eyes is way to light to be a tov eb.
I have to agree with Jeff, ebs. must follow the laws of genetics. Not much magic.
Here are pictures of my dark eb sister and brother Chimi and Changa. In the pictures the flash was on and it makes them look a bit lighter but they are actually pretty dark...not quite an extra dark