need afl code for change candlestick color when satisfied certain conditions

how to change candlestick color to white when buy and black when sell

for example
buy=RSI(14)<30
Sell=RSI(14)>70
:lol:

u can use following line:

Plot(C,"close",IIf(RSI()<30,colorWhite,IIf(RSI()>70,colorBlack,colorBlue)),styleCandle);


here candle will be blue if rsi 30 but <70.