HI Ravi,

You can make use of the UltraListBar ItemSelected Event.  The ItemEventArgs e exposes the selected Item object. You can then get acces to the

e.Item. Appearance object. where you can change ForeColor, ImageBackGround and many other properties.

Here are somea help links to the UltraListBar.

 http://help.infragistics.com/Help/NetAdvantage/NET/2007.3/CLR2.0/html/Infragistics2.Win.UltraWinListBar.v7.3~Infragistics.Win.UltraWinListBar.Item~Appearance.html

http://help.infragistics.com/Help/NetAdvantage/NET/2007.3/CLR2.0/html/Infragistics2.Win.v7.3~Infragistics.Win.AppearanceBase.html

http://help.infragistics.com/Help/NetAdvantage/NET/2007.3/CLR2.0/html/Infragistics2.Win.v7.3~Infragistics.Win.AppearanceBase_members.html

 http://help.infragistics.com/Help/NetAdvantage/NET/2007.3/CLR2.0/html/WinListBar_API_Overview.html

http://help.infragistics.com/Help/NetAdvantage/NET/2007.3/CLR2.0/html/WinListbar.html

here is a code snippet:

 private void ultraListBar1_ItemSelected(object sender, Infragistics.Win.UltraWinListBar.ItemEventArgs e)
        {
            e.Item.Appearance.BackColor = Color.Red;

            e.Item.Appearance.ImageBackground = Icon.ToBitmap();
            e.Item.Appearance.ImageBackgroundOrigin = Infragistics.Win.ImageBackgroundOrigin.Form;
            e.Item.Appearance.ImageBackgroundStyle = Infragistics.Win.ImageBackgroundStyle.Stretched;
            e.Item.Appearance.ImageBackgroundAlpha = Infragistics.Win.Alpha.UseAlphaLevel;
            e.Item.Appearance.AlphaLevel = 200;
            e.Item.Appearance.ForeColor = Color.Yellow;
        }