In wikipedia the page on mucus says that the colour of it can vary from transparent to dark green, but this is simply not the case as there are other colours too and I just wondered what the science of snot would be called? I mean I know its not going to be snotology or something like that but seriously I is there a name for the study of snot or where can I find a deeper study which would indicate why some of the different colour shades occur I have known snot go from transparent to yellow to dark green and brown, even black at one time from the soot in the LU tunnels http://en.wikipedia.org/wiki/Nasal_mucus
