Graham Murray"]

Are the points the same for every item in the series? Or do they differ? You could store them in an attached property on the Series and then bind at them on the series. 

Can you please provide an example of how to do this?

This sample should give you an idea of both how you can override the badge template for a series, and how you can store additional information about a series to bind against from the badge template.

<Window.Resources>
        <local:TestData x:Key="data" />
        
        <DataTemplate x:Key="customTemplate">
            <Rectangle Width="15" Height="15" 
                       Stroke="Black"
                       StrokeThickness="2"
                       Fill="{Binding Path=Series.(local:ChartInfo.LegendBrush)}"
                       />
        </DataTemplate>
    </Window.Resources>
    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>
        <igChart:Legend x:Name="legend1" Grid.Column="1" VerticalAlignment="Top" />
        
        <igChart:XamDataChart x:Name="theChart" Legend="{Binding ElementName=legend1}">
            <igChart:XamDataChart.Axes>
                <igChart:NumericYAxis x:Name="yAxis" />
                <igChart:CategoryXAxis 
                    x:Name="xAxis"
                    ItemsSource="{StaticResource data}"
                    Label="{}{Label}"/>
            </igChart:XamDataChart.Axes>
            <igChart:XamDataChart.Series>
                <igChart:ColumnSeries
                    LegendItemBadgeTemplate="{StaticResource customTemplate}"
                    x:Name="series"
                    Title="Series 1"
                    ItemsSource="{StaticResource data}"
                    XAxis="{Binding ElementName=xAxis}"
                    YAxis="{Binding ElementName=yAxis}"
                    ValueMemberPath="Value" 
                    local:ChartInfo.LegendBrush="Red"
                    />
                <igChart:ColumnSeries
                    LegendItemBadgeTemplate="{StaticResource customTemplate}"
                    x:Name="series2"
                    Title="Series 2"
                    ItemsSource="{StaticResource data}"
                    XAxis="{Binding ElementName=xAxis}"
                    YAxis="{Binding ElementName=yAxis}"
                    ValueMemberPath="Value"
                    local:ChartInfo.LegendBrush="Green"
                    />
                <igChart:ColumnSeries
                    LegendItemBadgeTemplate="{StaticResource customTemplate}"
                    x:Name="series3"
                    Title="Series 3"
                    ItemsSource="{StaticResource data}"
                    XAxis="{Binding ElementName=xAxis}"
                    YAxis="{Binding ElementName=yAxis}"
                    ValueMemberPath="Value"
                    local:ChartInfo.LegendBrush="Blue"/>
            </igChart:XamDataChart.Series>
        </igChart:XamDataChart>
    </Grid>

And code behind:

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }

    public class TestData
        : ObservableCollection<TestDataItem>
    {
        public TestData()
        {
            Add(new TestDataItem()
            {
                Label = "A",
                Value = 1
            });
            Add(new TestDataItem()
            {
                Label = "B",
                Value = 2
            });
            Add(new TestDataItem()
            {
                Label = "C",
                Value = 3
            });
            Add(new TestDataItem()
            {
                Label = "D",
                Value = 4
            });
        }
    }

    public class TestDataItem
    {
        public string Label { get; set; }
        public double Value { get; set; }
    }

    public class ChartInfo
    {
        public static Brush GetLegendBrush(DependencyObject obj)
        {
            return (Brush)obj.GetValue(LegendBrushProperty);
        }

        public static void SetLegendBrush(DependencyObject obj, Brush value)
        {
            obj.SetValue(LegendBrushProperty, value);
        }

        public static readonly DependencyProperty LegendBrushProperty =
            DependencyProperty.RegisterAttached("LegendBrush", typeof(Brush), typeof(ChartInfo));
    }

Hope this helps! Sorry about the delay.

-Graham