Rust colored – usually caused by pneumococcal bacteria (in pneumonia), pulmonary embolism, lung cancer or pulmonary tuberculosis. Brownish – chronic bronchitis (greenish/yellowish/brown); chronic pneumonia (whitish-brown); tuberculosis; lung cancer.

What organism causes rusty sputum?

Streptococcus pneumoniae: Rust-colored sputum.

What Colour is infected sputum?

As a general rule, sputum is dark green in the early stages of an infection and gradually lightens as the infection improves. It is the presence of an enzyme called myeloperoxidase that gives the sputum its green color, during an infection. Some infections may cause sputum to be yellow, gray, or rusty colored.