Gender?

[Kchud22]

I am new to chickens. I have heard that if there is waddle development around 6 weeks and its red that it is a good indication that I will have a rooster. Is this true? I got these chicks from TSC and they said that they were all hens. I know shocker that they got it wrong. Just curious. Thanks for the help

 

[Painted Calls]

Pullet.

The comb and wattles would be 3x that size and bright red if it were a cockerel.