Drag and drop SplitContainer control from toolbox on the window Form.

You can use both panel as a separate panel.

Properties of SplitContainer control:

·         Orientation - Gets or sets a value indicating the Horizontal or Vertical orientation of the SplitContainer panels.

·         BackgroundImage - Instead of a single color, an image can be displayed as the background. The image only appears in the splitter bar.

Change color of Panel in SplitContainer

Private Sub Form26_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
         Dim leftpanel As SplitterPanel = SplitContainer1.Panel1
         'change backcolor of Panle1
         leftpanel.BackColor = Color.PowderBlue
         Dim rightpanel As SplitterPanel = SplitContainer1.Panel2
         'change backcolor of Panle2
         rightpanel.BackColor = Color.RoyalBlue
End Sub

Run the project

Backcolor of both panel in splitcontainer is different because both panel works as a separate panel in splitcontainer control.

Collapse panel in splitcontainer

You can collapse one panel out of two panel in SplitContainer.

Private Sub Form26_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
         'Panel1 will be collapse at run time
         SplitContainer1.Panel1Collapsed = True
  End Sub

Panel1 will be collapse when apllication run.

Panel1 is collapse.