An undertone is just that, its not the main skintones you have.

Think about it, traditionally women did less outdoor work, got less exposure to the sun, and therefore had less of the reddish color that that would impart.

Also until recently men would do more physically intensive labor (hunter) while women would do less (gatherer) also increasing the males' reddish skin tones because of the flush associated with heavy physical labor. (I am not saying women did less work, just that the type women did was less likely to make a woman flush for all you trollies out there.)

So is it really any wonder that reddish undertones are more recognized as 'male', we've had centuries of conditioning for it.

Actually the pink for girls and red for boys is a recent development.

http://answers.google.com/answers/threadview?id=238733

Red was traditionally a male color, and as it faded to pink it was handed down to younger and younger males until infant boys were swaddled in the cloths.

Blue, considered a more delicate color was a preferred choice for women.

Go figure.