PS... the volume bar colors are the same as the green or red shown in the "bar" and "candle" type of graphs that you can show by clicking on the "line type" in the horizontal tool bar along the top. If you change your settings to either "bar" or "candle" then the volume bar colors will make more sense. (I use candle.) Here is the logic for Jan 15: We got a green bar because TQQQ was up relative to open that same day even though it was down vs. previous close.
It's all about that same day's direction. Green if higher than open price. Red if lower than open. For example, the bar will be green on a down day if it is up on that same day relative to open. Also wicks show price outside of the open and close (or current price if not closed yet). Good to pay attention to!