Thanks for writing.
Currently the candlestick cannot be changed to have different colors for rising/falling values since it already shows this information with its fill color. We will extend the candlestick series so that they can be more easily customizable out of the box.
In order to do this now you will have to inherit from CandlestickPointRenderer and change its drawing logic or provide a completely new point renderer. If you are a customer, you will have access to the source of the of whole chart so that you can modify and extend it as you require.
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