Setting CustomColors in a ColorDialog

Question

Custom color set in the color dialog are supposed to be set to {Blue, Blue} using the following code:

colorDialog1.CustomColors = new int[] { System.Drawing.Color.Blue.ToArgb(), 0xFF0000 };
colorDialog1.ShowDialog();

But, I am getting a different set {Black, Blue}:

Any idea What I am doing wrong here? Thanks.

Answer 1

You need to use OLE colors. The simplist way to achieve this is using the built in ColorTranslator object, e.g.

colorDialog1.CustomColors = new int[] { 
                                        ColorTranslator.ToOle(Color.Blue), 
                                        ColorTranslator.ToOle(Color.Red)
                                      };
colorDialog1.ShowDialog(); 

If you need to convert from HTML colors, you can also use the ColorTranslator.FromHtml method, e.g.

colorDialog1.CustomColors = new int[]
                                {
                                    ColorTranslator.ToOle(Color.Blue), 
                                    ColorTranslator.ToOle(ColorTranslator.FromHtml("#FF0000"))
                                };

Answer 2

If you have an array of colors, you can translate them using Linq:

colorDialog1.CustomColors = ThemeColors.Select(x => ColorTranslator.ToOle(x)).ToArray()

The ThemeColors array would be something like this:

public static Color[] ThemeColors
{
   get => new[]
   {
      Color.FromArgb(255, 185, 0),
      Color.FromArgb(231, 72, 86),
      Color.FromArgb(0, 120, 215),
      Color.FromArgb(0, 153, 188),
      Color.DarkOrange
   }
}

Note: Don't forget to add:

using System.Linq;

Answer 3

If you use ColorTranslator FromArgb, you can keep RGB colors in their proper order. For example, ColorTranslator.ToOle(Color.FromArgb(255, 0, 0)), is red. You can also use this to set colors that don't have a name, for example, the bright red ColorTranslator.ToOle(Color.FromArgb(255, 31, 33)),.