Here's one of my cochin males at 17 days old. You can see the color of his comb.
Here's a pic of their tail fins:
And here's a close-up of a female's head, I think between 3 and 4 weeks old:
Here's a pic of their tail fins:
And here's a close-up of a female's head, I think between 3 and 4 weeks old: