Yellow phlegm is normally a sign of an infection, or a case of the common cold. Greenish or brownish phlegm is nearly always a sign of infection. Greenish or rusty phlegm or phlegm with rusty spots can also be a sign of pneumonia. Coughing up brown phlegm is also a common symptom of excessive smoking.
A flowboard is a variation on a skateboard, combining aspects of surfing, skating and snowboarding.
A flowboard tends to put pressure on just 2 wheels of the board, rather than 4. This more focused weight distribution requires slightly more effort into keeping the board moving. For this reason, it is often ideal to ride it on downhill slopes.