HI,

In the Header property of the WebPanel, there is an ExpansionIndicator object  you can change the images of the expansion indictor. there are two properties - collapseImageUrl and ExpandedImageUrl - both of these values can be changed to an image that blends with its background color.

Here is a help link  to the Panel Header:

http://help.infragistics.com/Help/NetAdvantage/NET/2008.1/CLR2.0/html/Infragistics2.WebUI.Misc.v8.1~Infragistics.WebUI.Misc.PanelHeader_members.html

Here is a help link to the ExpansionIndicator object:

http://help.infragistics.com/Help/NetAdvantage/NET/2008.1/CLR2.0/html/Infragistics2.WebUI.Misc.v8.1~Infragistics.WebUI.Misc.TwoStateImageButton_members.html