Moving rectangles to different grid items in wpf

test.Add(new DataPoint(Brushes.Black));

<Grid.RowDefinitions>
    <RowDefinition Height="*"/>
    <RowDefinition Height="*"/>
    <RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
    <ColumnDefinition Width="*"/>
    <ColumnDefinition Width="*"/>
    <ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
 
<ListBox Name="list">
    <ListBox.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel />
        </ItemsPanelTemplate>
    </ListBox.ItemsPanel>
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Rectangle x:Name="Robot"   Fill="{Binding ColorName}"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

public class DataPoint
{
  public DataPoint(SolidColorBrush name)
  {
     ColorName = name;
  }

  public SolidColorBrush ColorName { get; set; }
}

public MainWindow()
{
    InitializeComponent();
    List<DataPoint> test = new List<DataPoint>();

    test.Add(new DataPoint(Brushes.Red));
    test.Add(new DataPoint(Brushes.Black));

    list.ItemsSource = test;
}