rooster and pullet feathering in different breeds

[cmfarm]

I know most breeds the pullets feather out sooner than the roos. But some colors/breeds this is not true of (I bred game chickens at one time and it worked for stripped chicks but not yellow). Does it work for Production Reds? Marans? I am selling some of these kinds that I hatched and straight run doesn't seem to be selling that well. They are 2 weeks old and I can definetly see some diffenences in feather growth. I just wanted to double check so I don't end up with angry customers will a bunch of roosters. I know it isn't 100% acurate (when I did it with the game chickens it was about 90% though, except the yellow ones). Any other breeds/colors it doens't work for (just curious). Thanks!