To analyse Tracey's problem I would not just take only the colour into consideration. The colour of a bile coming through your mouth in case of weared valve or other reasons may vary (I had it greenish once, when I was very sick with my pancreatitis, I could not eat anything, everything even tea would come out greenish and extremely bitter). The taste of bile is EXTREMELY BITTER!
I came from an area where bear bile is a common medicine and I know how it looks like when it is in its bag (bears gall bladder), it tastes even more bitter then ours.
Sorry, if the post hurted someone very friendly to animals.