Материал из .Net Framework эксперт
SystemPens.FromSystemColor
using System;
using System.Drawing;
using System.Windows.Forms;
class XMarksTheSpot : Form {
public static void Main() {
Application.Run(new XMarksTheSpot());
}
public XMarksTheSpot() {
Text = "X Marks The Spot";
ResizeRedraw = true;
}
protected override void OnPaint(PaintEventArgs pea) {
Graphics grfx = pea.Graphics;
Pen pen = SystemPens.FromSystemColor(SystemColors.ActiveBorder);
grfx.DrawLine(pen, 0, 0,
ClientSize.Width - 1, ClientSize.Height - 1);
grfx.DrawLine(pen, 0, ClientSize.Height - 1,
ClientSize.Width - 1, 0);
}
}