Koi or shubunkin or frankenstein -- how can I tell?

I'm wondering if someone can tell me what I might have in my pond :-)

I've got a 300 gallon pond with 3 one year old shubunkin, and a
handful of koi not much older than a year. I have dozens and dozens of
fry in every size from an eighth of an inch to two inches. Many of
them resemble the varicolored shubunkin, but some have plain and
subtle marks that look much more like the koi. Is it possible for the
black and white and florescent orange shubunkin to produce a fish
that's solid in color?

I also heard that the koi-shubunkin sterile "mules" were olive black
in color. Can anyone confirm that, or is it an old wives tale? I have
a fair amount of these...

Thanks!
Teri