How come none of the simpsons children ...

[Henny Penny]

... have blue hair like Marge and her sisters and her mother?

 

[cole]

The Simpson gene for yellow hair is dominant. (Or maybe they're not Marge's children).

 

[gipimann]

They dye their hair blonde

 

[jhegarty]

... have blue hair like Marge and her sisters and her mother?

because it's not her natural colour, it's blue dye #56

 

[ClubMan]

... have blue hair like Marge and her sisters and her mother?

I hate to shatter your illusions but it's a cartoon and they are not actually real people. Now - did anybody broach the issues of the tooth fairy and Santa Claus with you yet?

 

[rmelly]

The fact they haven't aged in almost 19 years was a bit of a giveaway...for me, anyway.

 

[ClubMan]

The fact they haven't aged in almost 19 years was a bit of a giveaway...for me, anyway.

They did in a few episodes.

 

[Ron Burgundy]

I hate to shatter your illusions but it's a cartoon and they are not actually real people. Now - did anybody broach the issues of the tooth fairy and Santa Claus with you yet?

Thanks for the bloody spoiler alert

 

[Henny Penny]

Marge's father also has blue hair ... Homer has a yellow head but black hair ..

 

[Purple]

I hate to shatter your illusions but it's a cartoon and they are not actually real people. Now - did anybody broach the issues of the tooth fairy and Santa Claus with you yet?

What, you mean Santa Claus and the tooth fairy are cartoons !?
... don't let my kids know; I brought them to Santa's grave last week (times are hard and I had to tell them something).