well differnet platforms sometimes have different color schemes but as a rule a red trade is at the bid, and green of course is the ask any color between means same as last trade price or inbetween the spread
As single trades you can only know if the trade went off on the bid side or ask, now what the signals are is how many trades in succession are hitting on that side of the offers, Obviously the more bid side trades indicate that a downtick in price could be coming, and opposite to that is if the trades are executed at the ask an uptikk is sure to come
GDSI is trading weird due to lack of interest, Not unlike a new trading stock that does not have many orders any buy whether bid side or ask can affect price movement, so with GDSI reading level 2 is almost useless
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