It's a nice idea, it may help for the traders like me. But I'm not agreeing all of your idea like you said that not all green bars more buyers, because according to my study of the candle sticks, the green bar means of buying so if we see a green bar with a very long low tail it means that there are many selling their tokens but the buyers overcome them all. This is only according to what I have learned.
Classical volume bar color is given by the candlestick color. If close price greater than open price then candle and volume bar color is green. But, that not necessary means more buyers...in most cases yes more buyers but there are cases where even if the candle is green in reality there were more sellers...The Buy vs Sell Volume indicator gives you a better insight of the volume distribution: buy volume vs sell volume.