Ahhhh, what?  I missed something here.  Anyway, my D.capensis
all green do come true from root cuttings.  Why wouldn't they?
I also expect it to come true via seed.  It's not a sport or
some such.  It is a mutant in which the plant produces no reddish
coloring.  Most species have such mutants and those that don't,
well it's only a matter of time before somebody finds them.
Dave Evans