Sexing dorking/sussex cross

Over Christmas we hatched some red dorking (cockerel) x light sussex (hens) chicks. We had a total of 14 chickens, 3 white and 11 brown. We did not try to sex them as day olds as we don't know what to do, but now it looks like the white ones are cockerels and the brown hens.

my question are:

Is this typical?
Will we be able to use this as a standard for sexing the chicks from day olds?

We plan on eating the cockerels, but it would be handy to know how many we have and how long the meat will last, as now we only have 3 birds to eat and need to grow more from scratch.

Thanks in advance
Louisa

Well if you were talking about some of the commercial brown hybrids, the hens generally take the colour of the cockerel, so in your case it looks like the same thing.  the hens are brown taking their colour from Dad!

But its not always the case!  Hope its right.  Will be so much easier for you!   

I have just found this web site

http://www.users.on.net/~greggles/sexing.html

It sort of answers my question.

Don't worry about breeding with the others. They are kept apart from the breeding birds and we won't hatch any out of the new ones.