Tubes, trousers and enlightenment

Mystery 1:
A couple of weeks ago, my American friend and I saw a guy sitting in a corner of our local MTR station wearing maroon trousers and a yellow t-shirt, which looked a bit like a uniform. My friend wondered aloud whether the man might be some kind of demi-monk due to the colour combination of his getup (the Dalai Lama did seem to be the chromatic inspiration for this look!). I said I didn't think monks wore pants. 
Mystery 2:Then, just last week, I saw these tubes on the floor in the MTR and I was quite puzzled as to what they were for (so I went over and took a picture):

Following which I went up the escalator and was enlightened:

Another poster change (I obviously did not pay enough attention to the trousers!).
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