Been sick with a cold for six days. Brown coming up when coughing. Chest hurts when breathing.?

Mgt. The brown appearance of your sputum is most likely related to old blood due to inflammation and infection of your airways. There is a possibility that you have developed pneumonia. Please seek medical care, and ask about having a chest radiograph.
Chest. A productive cough and painful breathing may indicate you have pneumonia. Be checked to see if you need treatment. All the best.