A red candlestick indicates that the price of an asset has fallen.
The upper boundary of the body is the price of the asset the moment the candlestick was opened.
The lower boundary is the price of the asset the moment the candlestick was closed.
The shadow under the body of the candlestick shows the minimum amount reached by the price of the asset over a specified period of time. The shadow above the body shows the maximum amount.
Sometimes candlestick charts may be black and white. In black-and-white charts, the red candlestick will be shown as black.