/////////////////// CODE ///////////////////////// using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Drawing.Drawing2D; namespace _125 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void panel1_Click(object sender, EventArgs e) { LinearGradientBrush lgb = new LinearGradientBrush(new Point(20, 70), new Point(70, 20), Color.Blue, Color.Violet); Graphics g = panel1.CreateGraphics(); ColorBlend cb = new ColorBlend(); cb.Colors = new Color[] {Color.White,Color.Black,Color.Blue,Color.GreenYellow }; cb.Positions = new float[] { 0, .33F, .66F, 1F }; g.FillRectangle(lgb, 20, 20, 100, 100); } } } /////////////////// OUTPUT ////////////...