Green phlegm from lower airway for 2 wks. No congestion & very mild cough. Clear chest CT a month ago. Small blood streaks this am. Cause for concern?

Green Phlegm. Anytime your secretions are green it indicates a possible infection... See your doctor.
See doctor... Coughing blood is called hemoptysis and it always requires an evaluation by a doctor. The most common cause is bronchitis but malignancy can also cause it and it should be ruled out. Chronic bronchitis, a form of copd, can cause the symptoms you describe and this also requires an evaluation by your doctor for diagnosis and treatment. If you are a smoker, you need to quit! see your doctor asap!