We started with seven Shubunkin about five years ago. We still have six, but I'm not sure how many are the original ones. I know three are definitely off-spring! Here are some images that will explain why these are not original!

Another view of the muddy-buddy. Its only additional color is on the leading edges of what I think are the pelvic fins.I assume this is simply the predominant colorings coming out. OTOH, all the three(?) other off-spring have been the 'normal' Shubunkin coloring. Or are they just 'flukes?!' Or, worse yet, caused by poor water/pond maintenance!
We have also had two non-Shubunkins grow up in the pond. I assume they were simply minnows or minnow eggs brought in from birds/frogs from some large ponds within 500 to 1,000 feet of our pond. Our back yard connects to ~140 acres of undeveloped land with at least three large ponds. Across our street the homes back up to a large golf course with additional large ponds. the end of our street (~1,000') is a city park with a very large and fish-stocked lake.
The off-spring are the ones pointed to by the arrows. The originals were all like the other three fish in this pic, multi-colored. I believe the largest fish in this image is one of a pair we called the 'Blues Brothers' because they were almost identical and had lots of blue coloring.
The two off-spring showed up last year. I call the smaller one an 'albino' but it is actually more flesh colored. The other one is not really black but a brownish/grey-black. Not particularly pretty as far as color but it has larger, more flowing fins than it's more colorful parents/cousins!
This is the last of the off-spring, also appeared last year. It has the same huge, flowing fins but about a dozen colored spots to 'prove' it's lineage!

Another view of the muddy-buddy. Its only additional color is on the leading edges of what I think are the pelvic fins.
We have also had two non-Shubunkins grow up in the pond. I assume they were simply minnows or minnow eggs brought in from birds/frogs from some large ponds within 500 to 1,000 feet of our pond. Our back yard connects to ~140 acres of undeveloped land with at least three large ponds. Across our street the homes back up to a large golf course with additional large ponds. the end of our street (~1,000') is a city park with a very large and fish-stocked lake.