Autosexing Eggs

I would really really love some hatching eggs, but i can't risk getting boys (very small garden)

Wouldn't it be really cool if you could get autosexing eggs!
Cause the last thing to be formed on an egg is the shell, so how cool would it be that the shell colour was determined by the sex of the baby inside
(maybe, white or pale for not fertilized, blue for a boy, dark brown for a girl)
then, we could eat the blue eggs and hatch (or eat) the girl eggs (or grow them into broilers).

It would revolutionize the egg industry, and stop wasting so many boy chickens!