@heathert My sputum goes from clear to cloudy white to light yellow to darker tan. I usually get darker colored sputum right after I get out of bed in the morning. As the day goes along, it becomes lighter. Darker colored sputum could mean that there is some kind of infection in your lungs. But it is not necessarily tied to MAC. For example, if you have bronchitis or pneumonia, your sputum could be of a darker color, like yellow or green.