A green candle is a candlestick whose body commonly indicates that price closed above its opening level during the selected interval. On an unfinished candle, the latest price acts as the provisional close, so the color can still change before the period ends. Color conventions differ by chart settings and market; green does not universally mean an increase.
Reading a completed candle
Under the common green-up convention, an opening price of 100 and a closing price of 105 create a green body spanning those levels. If the period’s high was 108 and low was 98, the upper and lower wicks extend to those extremes. The body measures the opening-to-closing move, not the full trading range.
What the color cannot tell you
A green candle can still close below the previous candle’s close: opening at 100 and closing at 105 is green even if the earlier close was 110. It also does not count buyers or prove that more units were bought than sold; every matched trade has both sides. Volume, surrounding candles and the timeframe provide additional context, but a green candle alone does not predict continued gains.