Gha!
Well technically a bb is not the best way to clasify color. Indigo is generaly "bluer" than the shade you use...of course there is also indigo blue which is blue with a purple shade...vs indigo which is purple with a blue shade...
Oh and Onyx != black.
"Onyx is a translucent stone with pleasing and highly varied color and markings. It is closely related to marble." -
http://www.onyxartinc.com/what_is_onyx.shtml
Although Cougar, puma, panther, and mountain lion are indeed the same thing.
So technically OnyxCougar means "A large feline the color of which may be varied".
But thats if you insist on getting technical...