Solved.
I have used 'Invalidate()' method to fire paint event.
Private BorderColor_ As Color
Public Property BorderColor() As Color
Get
Return BorderColor_
End Get
Set(ByVal value As Color)
BorderColor_ = value
Invalidate()
End Set
End Property
Private Sub SplitCellControl_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
Dim _PenBorder As New Pen(Color.Black, 1)
_PenBorder.Color = BorderColor
e.Graphics.DrawRectangle(_PenBorder, 0, 0, MyBase.Width - 1, MyBase.Height - 1)
_PenBorder.Dispose()
End Sub