I found the answer at this page, thanks again. Finally, if you do enable the "Colored Prices" option for a SharpChart, here are the rules that we use:
If the previous day's closing value is less than or equal to the closing value for the current day, draw the current day's candlestick in black. If the previous day's closing value is more than the closing value for the current day, draw the current day's candlestick in red.