Sangreaal: Like so much in koi, what was once a truism no longer is.

Unfortunately, there are few photos of koi from the 1940s and before. Some time back Ray Jordan posted a photo of a kage type Showa that appears in Amano's General Survey of Fancy Carp published in English in 1968. It gives an impression of what the early Showa were like. You can also get something of an impression from Kiefer's recent thread on the progress of his Shiro Utsuri fry... check the ones that are heavy with sumi with white starting to break through. The Utsuri group are koi derived from black koi ... a smokey sort of black, more like charcoal and soot. At one point in their history, you would not have had a problem envisioning the fish as black with patterning overlaid. As the sumi has been improved, the shiro improved, etc., etc., the base color has become white. But, they are still derived from kuroki ... black fry. Today, in the Showa worth having, I think referring to them as "black based" is more an anachronism, but there is still truth in it if you think of it as a reference to the genetic root, not the phenotype you see.