Everyone knows that all three girls had blonde hair that matched that of Carol (the theme song goes, "All of them had hair of gold ... like their mother ... the youngest one in curls!"), while the boys had black hair to match Mike, their father.

Question: How come there were no brunette girls or blonde boys? Or redheads, for that matter? Genetically, it would be possible, assuming that the girls had a dark-haired biological father (Mr. Martin) and the boys had a blonde biological mother before "the one day that the lady met this fellow" (think of that picture Bobby carried in the first episode!).

Thoughts, anyone?

Oh sure, those combinations are possible. But Sherwood Schwartz, the creator, has always said that the hair color would help people remember which kids belonged to whom. I used to think this reasoning was kind of silly. But then again, I can never remember which kids go with which parent on "Step by Step", so I think Sherwood had a good point.

BTW, before the adults were cast, he cast an extra six kids: three blond boys and three brunette girls, in case Mike wound up being blond and Carol was a brunette. I'd be curious to know what happened to those kids, and if they're bitter about losing out to the kids we know as the bunch.

Originally posted by TV Guy
But then again, I can never remember which kids go with which parent on "Step by Step", so I think Sherwood had a good point.

I do remember watching Step By Step (which, BTW, was billed as a nineties version of TBB, to get back on topic), and here is the way the children were owned:

Frank Lambert: J. T. (brunette), Al (as in Allison; blonde), (I forget who that kid was that was played by Josh Byrne!; brunette)
Carol Foster: Dana (blonde), Karen (brunette), Mark (blonde)

Good thing Jan's brunette wig never caught on. It would have thrown off the whole balance of the show.