funny coloured poop?

hey all
now i have a little worry about 3 of my snakies.

a few weeks back my male, scales, pooped normally, however the white had a bit of green to it, i just thought to myself that id keep an eye on him, all was fine up until a few days ago, i cleaned out 3 of mine only to find that all their poop, the white bit had a bit of green to it.
i checked my other girlie who is on the other side of my room from the other 3 and her poop is absolutely fine.

i always thought that it was a vitamin deficiency but i called the vet today anyway to get his advice as he said as long as they are shedding, drinking and eating fine it should be okay. he said it could be a change of environment of diet.

now my question is has anyone else experienced this?
if so what had caused yours?

as i have not changed anything at all lately, i feed them all fortnightly as they are all adults now and are on adult mice or rat weiners and i put vitamins in their drinking water.

i just found this situation weird that my 3 snakies stacked on top of one another has this problem and the one on the other side is fine. the very first thing i thought of was that is was contagious.

any help or advice would be very much appreciated.
thanx for listening to me ramble

My adults poop would change, but i put it down to feeding a chick 1 feeding and a mouse the next feeding, the mouse was normal and the chicks poop was a little "off" white and occasionally a light green.

Can't think of anyother reason to help you out, but thats my experience with "green poop".

oh ok, now my male has recently been hanged to rats so could that be it then?

thanx for your reply oldhand.