It truly becomes easier as you experience it. The only colors that are difficult to sex are white, slate, and tuxedo. I can usually judge sex in these colors around 6 or 7 weeks of age by size and behavior. I'm normally about 80% accurate with this method (I have had small females and large males before) . But the only really accurate way to sex these colors is to vent sex them after they reach sexual maturity. Hens have a larger cloaca than the males. Sometimes, however, with tuxedos, you can find some red feathers to be sure it is a male.
