public class HoverButtonCellType : FarPoint.Win.Spread.CellType.ButtonCellType
{
    public override void PaintCell(Graphics g, Rectangle r, FarPoint.Win.Spread.Appearance appearance, object value, bool isSelected, bool isLocked, float zoomFactor)
    {
        if (appearance.MouseOver)
        {
            VisualStyleElement element = VisualStyleElement.Button.PushButton.Hot;
            if (VisualStyleRenderer.IsElementDefined(element))
            {
                FpVisualStyleRenderer vsr = new FpVisualStyleRenderer(element);
                vsr.DrawBackground(g, r);

                //use same logic as VerticalAlignment for HorizontalAlignment if needed. 
                //sample use Horizontal Center only
                TextFormatFlags formatFlags = TextFormatFlags.HorizontalCenter;
                switch (appearance.VerticalAlignment)
                {
                    case CellVerticalAlignment.Bottom:
                        formatFlags |= TextFormatFlags.Bottom;
                        break;
                    case CellVerticalAlignment.Top:
                        formatFlags |= TextFormatFlags.Top;
                        break;
                    default:
                        formatFlags |= TextFormatFlags.VerticalCenter;
                        break;
                }

                int shadowSize = ShadowSize;
                r.Height -= shadowSize * 3;
                TextRenderer.DrawText(g, Text, appearance.Font, r, Color.Red, formatFlags);
                return;
            }
        }

        base.PaintCell(g, r, appearance, value, isSelected, isLocked, zoomFactor);
    }
}