Changing Plot Element Colors
To change the colors assigned to the plot elements such as bars and pies(depending on chart type), you can either change the Palette property to one of the predefined color palettes or you can create a custom palette, such as:
Brush[] customBrushes = new Brush[2] { Brushes.Blue, Brushes.Orange };
c1Chart1.CustomPalette = customBrushes;