Hello, I hope you are feeling better, I'll prescribe something for you after I answer your question. :-)
Here is the answer to your question:
Phlegm may be of several different colors.
"Healthy" phlegm is normally clear or white.
Yellow phlegm is normally a sign of an infection, or a case of the common cold.
Greenish or brownish phlegm is nearly always a sign of infection. Greenish or rusty phlegm or phlegm with rusty spots can also be a sign of pneumonia.
Coughing up brown phlegm is also a common symptom of excessive smoking. This is due to resin sticking to the viscous texture of the phlegm and being ejected by the body.
If you listen to my grandmother and it helps will you write back to say I'll pay more attention to what older people say in the future? :-) In the morning and at bedtime hot tea (not coffee); every four to six hours take two or three regular aspirins (Bayers); a hot shower not bath as many times a day as possible; lastly drink water until you feel like a sponge. (A lot of water)!! Sounds dumb I know, but we know there is no cure for a cold but this really makes you feel better and sometimes shortens the infected period. Trust me would I lie? Ok, I see your point trust my late grand mother then! God Bless you my late grandmother and the Southern people..
My Grandmother God Rest Her Soul