A glider who is severly ill....feet may turn a sickening yellow color. However...I have never heard of them turning green. Vomiting is common when a glider is severly ill also.
As to the green feet...hope you are not using a litter that has chloraphill(sorry cannot spell at the moment). Gliders become severly ill from it and die. Dot sure if it is from inhaling the odor if they eat the stuff is what's kills the glider. But either way...a glider's system appears to be poisioned from it.
Have the
vet do a blood test, fecal float and smear as well as a UA. Also, if not on the BML
diet plan then suggest an X-ray to determine bone density for HLP.
Good Luck.