The gradient serves as the background color to the channels.
Go to the Enterprise Sample CSS directory located under the portal data directory, PortalServer-DataDir/portals/portal-ID/web-src/enterprise/css.
Modify the CSS file in the appropriate place.
For example, replace the image channel-gradient-orange.gif with your new color gradient image.
The following is a listing of the location of JSP and image files for the Enterprise Sample logo and banner.
Files altShortBody-asc-logo.gif and asc-logo-8.png
Located at PortalServer-DataDir/portals/portal-ID/web-src/enterprise/images directory
File Header-alone-no-logo.jpg
Located in PortalServer-DataDir/portals/portal-ID/web-src/enterprise/images directory
File title.jsp
Located at PortalServer-DataDir/portals/portal-ID/desktop/enterprise_sample
File anonymous.jsp
Located at PortalServer-DataDir/portals/portal-ID/desktop/enterprise_sample/ASCTabContainerProvider
PortalServer-DataDir/portals/portal-ID/web-src/enterprise/css
PortalServer-DataDir/portals/portal-ID/web-src/enterprise/css