I was working in a medical center during cold & flu season. The waiting room was filled to capacity. The Physicians & PAs were seeing everyone with these symptoms. A patient asked "What does the spit look like if you have bronchitis?", the PA reported "green". After the patient left, I don't know what came over me, - but, I sang-
"If it is clear or it is white, you are alright. If it is yellow or green, you need to be seen. If it is brown, put your cigarettes down. And if it is red, you will need a hospital bed."