To create a fill color for rising stock prices, use the FillTransparent and SymbolStyle color properties.
c1Chart1.ChartGroups(0).HiLoData.FillTransparent = False
c1Chart1.ChartGroups(0).ChartData.SeriesList[0].SymbolStyle.Color = Color.Yellow
•C#
c1Chart1.ChartGroups[0].HiLoData.FillTransparent = false;
c1Chart1.ChartGroups[0].ChartData.SeriesList[0].SymbolStyle.Color = Color.Yellow;