private void button6_Click(object sender, EventArgs e)
{
    //创建一个新AlgorithmicColorRampClass对象
    IAlgorithmicColorRamp algColorRamp = new AlgorithmicColorRampClass();
    //创建起始颜色对象
    IRgbColor startColor = new RgbColor();
    startColor.Red = 255;
    startColor.Green = 0;
    startColor.Blue = 0;
    //创建终止颜色对象
    IRgbColor endColor = new RgbColor();
    endColor.Red = 0;
    endColor.Green = 255;
    endColor.Blue = 0;
    //设置AlgorithmicColorRampClass的起止颜色属性
    algColorRamp.ToColor = startColor;
    algColorRamp.FromColor = endColor;
    //设置梯度类型
    algColorRamp.Algorithm = esriColorRampAlgorithm.esriCIELabAlgorithm;
    //设置颜色带颜色数量
    algColorRamp.Size = 5;
    //创建颜色带
    bool bture = true;
    algColorRamp.CreateRamp(out bture);
    //使用IEnumColors获取颜色带
    IEnumColors pEnumColors = null;
    pEnumColors = algColorRamp.Colors;
    //设置５个picturebox的背景色为产生颜色带的５个颜色
    this.pictureBox1.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
    this.pictureBox2.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
    this.pictureBox3.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
    this.pictureBox4.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
    this.pictureBox5.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
}
来自：http://bbs.esrichina-bj.cn/ESRI/thread-46784-1-1.html

private void button6_Click(object sender, EventArgs e)
        {
            IRandomColorRamp pRandomColorRamp = new RandomColorRampClass();

            //** 制作一系列介于橘黄色和蓝绿色之间的随机颜色
            pRandomColorRamp.StartHue = 40;
            pRandomColorRamp.EndHue = 120;
            pRandomColorRamp.MinValue = 65;
            pRandomColorRamp.MaxValue = 90;
            pRandomColorRamp.MinSaturation = 25;
            pRandomColorRamp.MaxSaturation = 45;
            pRandomColorRamp.Size = 20;
            pRandomColorRamp.Seed = 23;

            bool bture = true;
            pRandomColorRamp.CreateRamp(out bture);

            IEnumColors pEnumColors = pRandomColorRamp.Colors;

            //设置５个picturebox的背景色为产生颜色带的５个颜色
            this.pictureBox1.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
            this.pictureBox2.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
            this.pictureBox3.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
            this.pictureBox4.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
            this.pictureBox5.BackColor = ColorTranslator.FromOle(pEnumColors.Next().RGB);
        }