Greenish mucus can come from your bronchioles such as in the case of Acute Bronchitis. or Acute Sinusitis. Tannish mucus can come from your lungs, such as in Pneumonia. Both can be brought up by coughing. Brown mucus might come from your throat if irritated and inflammed. Yellowish mucus might indicate some sinus infection; colds or the flu. . Spit and sputum which are usuallly clear can come from your saliva as secreted by the salivary glands. Mucus that are clear can sometimes be the case of allergies. such as allergic rhinitis.
Mucus is normally clear and does not represent any sickness unless it becomes excessive and/or discolored. You often discharge bloody or brownish mucus when your sinuses are engorged and blood mingles with your mucus. Brown mucus is a common complain of smokers, because tobacco smoke can better engorge your sinuses.
When you have nasal polyps or irritated mucus membranes, your mucus is blood stained and looks brownish or bloody. Blood stained mucus is also the case with an irritated throat. Alcohol consumers often have engorged throats and bronchi, thus coughing up blood stained or brownish mucus.
Several other things may cause your mucus to be brown. These include the following:
Certain foods, such as chocolate, other snacks, garlic and red wine
Bacteria and viruses
Although these can discolor your mucus to a brown color, your mucus may take several other colors due to various causes
Other mucus colors include clear, white, yellow, and green.