Sexing my 5 week old mixed breed chicks!

[IslandAcres]

Hello! I would appreciate any input into sexing two of my mixed breed chicks. My 6 other chicks are quite clearly roos or hens, but these two have me a little perplexed. Thanks for your help!

 

[Brooks_]

Red is a pullet, black is a cockerel. Or I'm wrong on one or both counts.

 

[Chicalina]

I vote both pullets. And I usually vote cockerel