In C# you can draw a shape on any control. For example:
System.Drawing.SolidBrush b = new System.Drawing.SolidBrush(Color.Blue);
System.Drawing.Graphics g = System.Drawing.Graphics.FromHwnd(control.Handle);
float width = 50;
float height = 25;
g.FillRectangle(b, 0, 0, width, height); // draw blue rectangle in upper left corner of control
System.Drawing.Graphics g = System.Drawing.Graphics.FromHwnd(control.Handle);
float width = 50;
float height = 25;
g.FillRectangle(b, 0, 0, width, height); // draw blue rectangle in upper left corner of control