I know you're hoping for EEs. EEs can look similar to Partridge Plymouth Rocks and Welsummers, but they won't look so uniform in the coloring and leg coloring. Your pairs of chicks you have pictured all look exactly the same as their buddy - EEs will not be so exact in their feather coloring and won't look 'exactly' like these other types of chickens.
Plus, both chicks in each pair are clean-faced. You may happen to get 1 clean-faced EE, but wouldn't get 2 clean faced EEs that look the same in 1 shipment.
Ignore the colors of your chicks and look for muffs/beards. EEs can come in all colors - they do occasionally come without muffs/beard, but most of the time that's the big identifying feature. EEs should also have a pea comb (like the comb on your brahmas or at least smaller than your chicks with straight combs). Look for greenish legs - most of my EEs have grey/slate legs, but if you have any chicks with green legs, that's a tell-tell sign of an EE. How about that buff/black colored chick on post #3, first picture? Does she have feathered legs? If not, check her face for the muffs/beard.
Here's a couple 7 week old EEs that are similar in color as to what you're thinking of as EE type coloring, but notice how different they are from each other - also, even though they are similar, you can't mistake them for a Welsummer or other purebred chick. Also, note how their combs are smaller than chicks with straight combs (note the difference in size from their combs versus the the barred rock's comb in the first pic and the white leghorn's comb in the 2nd pic). The muffs/beards in these 7 week old chicks are hard to see in the pics - their beards got bigger as the chicks grew.
This is a pretty EE girl I received in an online shipment of EEs - just to show a different color EE and with very obvious muffs/beard.
Mid pic is a bit older pic.Other two from yester.
