Random dark spots on chickens legs

[My Very First 6 Chickens]

Hello my chicken friends! I have 6 20 week old GLW’s pullets who are yet to lay. My question is about circular dark spots on the legs. Random pattern. Only a couple of the girls have them i noticed, but i didnt inspect them yet. Thanks in advance!

 

[Ebony Rose]

Pictures are worth a thousand words. Have any that you can share?

 

[My Very First 6 Chickens]

Pictures are worth a thousand words. Have any that you can share?

Oh! Thats a tough ‘feet’! I followed them around for a bit just now but dont wanna try to hard and disturb them while they freerange. I’ll try again. In the meantime, i’m not overly concerned, more just curious. Its not on all of them and they are almost like a deep dark purple color but light if that makes sense. They have yellow feet and legs. They are getting ready to lay so i was wondering if there was a correlation. Learning curves! I’ll still try for the pic