6 week old RIR gender?

[clickdb]

these three chicks are 6 weeks old, and they are the only ones of my flock that I am not sure on gender. their combs are not very developed, but I don't want to be surprised by a late bloomer. The pics make their combs look redder than they are.
From left to right: Squeaker, Ol' Red, & Little Foot.

Squeaker:

Ol' Red:

Little Foot:

And Bonus chick, Princess who is photo bombing the first pick (known pullet)

 

[BantamLover21]

Little Foot looks like your only possible cockerel for now, but they're a little young to be sure.

 

[Michael OShay]

Given the size and redness of its comb at 6 weeks, I'm thinking that Little Foot is a cockerel. The others appear to be pullets.