If they sold those birds as guaranteed females they should be ashamed of themselves and refund your money or swap them out. That much red/orange on the chest is a definite male. I only see one female (top in first pic) and the rest are males.
Some males do take a little longer to feather in, and mine typically start towards the bottom of the chest and work upwards. So some do still have speckles towards the neck at 4 weeks but the red/orange is a dead giveaway it's a boy.
Some males do take a little longer to feather in, and mine typically start towards the bottom of the chest and work upwards. So some do still have speckles towards the neck at 4 weeks but the red/orange is a dead giveaway it's a boy.