I am using the following code to add two panes to my control.  

I would like the top pane to take up  75% of the space available by default.  

How can I set the splitter distance? 

Also, can I control the background and height of the splitter?

<igDock:XamDockManager Name="xamDockManager1" Grid.Row="2">
                <igDock:XamDockManager>
                    <igDock:DocumentContentHost Padding="-1">
                        <igDock:SplitPane SplitterOrientation="Horizontal">
                            <igDock:TabGroupPane Padding="-3">
                                <igDock:ContentPane Header="Results" AllowClose="false">
                                    <ContentControl Content="{Binding GridVM.View}"></ContentControl>
                                </igDock:ContentPane>
                            </igDock:TabGroupPane>
                            <igDock:TabGroupPane Padding="-3">
                                <igDock:ContentPane Header="Cross Section Data" AllowClose="false">
                                    <ContentControl Content="{Binding GridVM.CrossSectionVM.View}" ></ContentControl>
                                </igDock:ContentPane>
                            </igDock:TabGroupPane>
                        </igDock:SplitPane>
                    </igDock:DocumentContentHost>
                </igDock:XamDockManager>
            </igDock:XamDockManager>