Okay, so I went out to feed them today with some colorful painted toenails.
The big toe captain (lol, Seinfeld reference) had red and white respectively, and #2 were yellow and blue (I didn't have a decent green paint) on each foot.
...The poults went for the YELLOW toenail! Very interesting! I thought the red would be the winner for sure.
It also seems like they were very friendly in the beginning, but as they became fuller, became more standoffish... Perhaps it has something to do with weather and hunger, not neccesarily color. I'm sure if I didn't do this everyday, they'd be much more willing to get closer for some long overdue food!! (As stated, they are wild free-roaming, so me not giving food would not starve or malnourish them-- I'm not cruel!!)