I found the example of what I was talking about. These are 5 week old silkied Cochins from @pipdzipdnreadytogo
Pullet:
Cockerel:
With this batch of chicks, it was extremely obvious by 7 weeks who was a pullet and who was a cockerel (besides the fact that a few of them were crowing before...
The Mille Fleur is a cockerel.
The only reason I hesitate on saying the Cochin is a cockerel, is that from what I've seen, Cochin cockerels normally have even larger, redder combs by 5 1/2 weeks.However, I would say cockerel unless proven otherwise