FarPoint.Win.Spread.DrawingSpace.PSGradient g = new FarPoint.Win.Spread.DrawingSpace.PSGradient();
g.Style = FarPoint.Win.Spread.DrawingSpace.GradientStyle.RadialIntoCenter;
g.Sections[0].Color = Color.Navy;
g.Sections[0].AlphaBlend = 128;
g.Sections[1].Color = Color.Magenta;
g.Sections[1].AlphaBlend = 255
FarPoint.Win.Spread.DrawingSpace.ArrowShape arrow = new FarPoint.Win.Spread.DrawingSpace.ArrowShape(fpSpread1);
arrow.CanSize = FarPoint.Win.Spread.DrawingSpace.Sizing.HeightAndWidth;
arrow.CanMove = FarPoint.Win.Spread.DrawingSpace.Moving.HorizontalAndVertical;
arrow.Anchor = 20;
arrow.SetBounds(15, 15, 50, 50);
arrow.Gradient = g;
fpSpread1.ActiveSheet.AddShape(arrow);