Can I tell gender at 6 weeks?

[HomeFarmlove]

I have several breeds about 6 weeks old. I am wondering if it is too early to tell if they are males or females.
Here are a few pics to see if any of you have an idea. Thanks so much!

 

[HomeFarmlove]

 

[Dottie the Chicken]

The one closet to the camera looks like a cockerel.

 

[HomeFarmlove]

Sorry, learning how to post pics. Didn’t mean to make 3 posts!

 

[HomeFarmlove]

Thank you. And the black one?