The logo image is defined in the themes in the display profile. The related theme properties are:
The brand image on the left of the header.
The brand image in the center of the header; if there’s no need to have the second image, then use spacer.gif.
The background color for the left image file.
The background color for the center image file.
The width of the left image file.
The image that is displayed in the Theme/preset Themes page.
Log in to the Sun Java System Portal Server management console.
Download the display profile XML fragment.
Modify the relevant theme properties and upload the display profile.
Copy the new image into PortalServer-base/web-src/images directory.
Run PortalServer-base/bin/psadmin redeploy --adminuser amadmin --passwordfile passwordfile --portal portal-ID command to deploy the new image.
Reload the Desktop to verify the change.