Okay, so probably not an OEGB then. For those two, I would wait until they feather in more, and then post some new photos.
You're right, olive eggers are mixes. But, they generally have a certain way that they look, and those three look nothing like OEs.
Does the comb look like either of these?
At this age, it's kind of hard to tell anything for sure, however I can tell you some things. The gray one is an Easter Egger.
The two chipmunk ones are two different breeds. It's kind of hard to tell from the picture if the one in the back has muffs. If it does, it's an EE. If not, then it...