Yes, Fil, you are right, the colour of healthy fresh bile is light yellow, a bit ember like.
I was once in a hospital going through a procedure called something like "analysis of bile". I had to swallow long rubber tube with some little metal part on top. Then they put a bottle of warm mineral water with something else inside by body through the tube. I had to lay on a special bed for one hour or so while my bile was slowly coming out of me through the tube into 10 test glass tubes.
Sounds like x-files I know, but that is how they do it.
So, my bile was fine and had light yellowish colour, the consistency was something like liquor. I even tried to smell it, but felt nothing but some very indistinctive smell, the one we would feel in a field after rain.
At the same time in that room there were more people of older age (I was 20 y.o. then) and I saw that some of them had their bile looking really terrible. Dark green uneven with some strange stuff floating in it. That was obviously sick bile.
A few days ago I read somewhere that toxic bile gets this dark green colour.
As for vomiting with bile, it is true, it has something to do with bad condition of a valve that suppose to let the bile only one way. It happened to me when I was really sick with my pancreatitis. That was the time when I ended up in a hospital going through all kinds of weird procedures and checks like one, described above. The doctor said that my valves were screwed up due to my restless and very emotional nature, she believed they sort of get weared out.
Well, these are some notes from my own experience. I hope someone may find them useful.