public class PaletteColorCollection :
    NotificationCollection<Color>

Public Class PaletteColorCollection
    Inherits NotificationCollection(Of Color)

using System.Collections.Generic;
using System.Drawing;
using DevExpress.DashboardCommon;
using DevExpress.XtraEditors;

namespace Dashboard_ChoroplethMapCustomPalette {
    public partial class Form1 : XtraForm {
        public Form1() {
            InitializeComponent();
            // Loads a dashboard that contains a choropleth map with the default palette.
            Dashboard dashboard = new Dashboard();
            dashboard.LoadFromXml(@"..\..\Data\Dashboard.xml");

            // Gets the ValueMap object that provides data for coloring map shapes.
            ChoroplethMapDashboardItem map = (ChoroplethMapDashboardItem)dashboard.Items[0];
            ValueMap populationMap = (ValueMap)map.Maps[0];

            // Creates CustomPalette and CustomScale objects.
            CustomPalette customPalette = new CustomPalette();
            CustomScale customScale = new CustomScale();

            // Creates lists of custom colors and range stops.
            List<Color> customColors = new List<Color>();
            List<double> rangeStops = new List<double>();

            // Specifies that the absolute scale is used to define a set of colors.
            customScale.IsPercent = false;

            // Specifies custom colors and corresponding range stops.   
            customColors.Add(Color.LightBlue); rangeStops.Add(100000);
            customColors.Add(Color.SkyBlue); rangeStops.Add(1000000);
            customColors.Add(Color.LightCoral); rangeStops.Add(10000000);
            customColors.Add(Color.Tomato); rangeStops.Add(100000000);
            customColors.Add(Color.Maroon); rangeStops.Add(1000000000);

            // Adds custom colors and range stops to a custom palette and corresponding custom scale.
            customPalette.Colors.AddRange(customColors);
            customScale.RangeStops.AddRange(rangeStops);

            // Specifies a custom palette and scale for the ValueMap object.
            populationMap.Palette = customPalette;
            populationMap.Scale = customScale;

            // Sets the customized dashboard as a currently opened dashboard.
            dashboardViewer1.Dashboard = dashboard;
        }
    }
}

Imports System.Collections.Generic
Imports System.Drawing
Imports DevExpress.DashboardCommon
Imports DevExpress.XtraEditors

Namespace Dashboard_ChoroplethMapCustomPalette
    Partial Public Class Form1
        Inherits XtraForm

        Public Sub New()
            InitializeComponent()
            ' Loads a dashboard that contains a choropleth map with the default palette.
            Dim dashboard As New Dashboard()
            dashboard.LoadFromXml("..\..\Data\Dashboard.xml")

            ' Gets the ValueMap object that provides data for coloring map shapes.
            Dim map As ChoroplethMapDashboardItem = CType(dashboard.Items(0), ChoroplethMapDashboardItem)
            Dim populationMap As ValueMap = CType(map.Maps(0), ValueMap)

            ' Creates CustomPalette and CustomScale objects.
            Dim customPalette As New CustomPalette()
            Dim customScale As New CustomScale()

            ' Creates lists of custom colors and range stops.
            Dim customColors As New List(Of Color)()
            Dim rangeStops As New List(Of Double)()

            ' Specifies that the absolute scale is used to define a set of colors.
            customScale.IsPercent = False

            ' Specifies custom colors and corresponding range stops.   
            customColors.Add(Color.LightBlue)
            rangeStops.Add(100000)
            customColors.Add(Color.SkyBlue)
            rangeStops.Add(1000000)
            customColors.Add(Color.LightCoral)
            rangeStops.Add(10000000)
            customColors.Add(Color.Tomato)
            rangeStops.Add(100000000)
            customColors.Add(Color.Maroon)
            rangeStops.Add(1000000000)

            ' Adds custom colors and range stops to a custom palette and corresponding custom scale.
            customPalette.Colors.AddRange(customColors)
            customScale.RangeStops.AddRange(rangeStops)

            ' Specifies a custom palette and scale for the ValueMap object.
            populationMap.Palette = customPalette
            populationMap.Scale = customScale

            ' Sets the customized dashboard as a currently opened dashboard.
            dashboardViewer1.Dashboard = dashboard
        End Sub
    End Class
End Namespace