This example uses two LinearGradientBrushes to draw an ellipse that has a sort of three-dimensional button-like appearance. The key is to outline the ellipse and fill it with brushes whose gradients point in opposite directions. The following code fills the ellipse with a brush that changes from lime to dark green in the direction 225 degrees. It then outlines it with a brush that flows from lime to dark green in the opposite direction: 45 degrees.

// Fill the ellipse.
using (LinearGradientBrush br =
    new LinearGradientBrush(rect,
        Color.Lime, Color.DarkGreen, 225f))
{
    e.Graphics.FillEllipse(br, rect);
}

// Outline the ellipse.
using (LinearGradientBrush br =
    new LinearGradientBrush(rect,
        Color.Lime, Color.DarkGreen, 45f))
{
    using (Pen pen = new Pen(br, 20f))
    {
        rect.X += 10;
        rect.Y += 10;
        rect.Width -= 20;
        rect.Height -= 20;

        e.Graphics.DrawEllipse(pen, rect);
    }
}