The colors don't mean much. They are red if the trade goes through on the bid or causes the pps to go down, and they are green if it goes through on the ask or causes the pps to remain the same or go up. Classifying a trade as a buy or a sell is rather meaningless, since all trades are both a buy and a sell. Someone sells to someone who buys. The most important thing to note about today is that the pps went up over 15%.
It's also important to note that with all today's volume, the pps never fell below yesterday's close and ended up over 15% higher. Which some would call a "green" day.
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