Perhaps you can use custom style sheets in eazyBI staging to change the background color.
Please share the file with everbody here by posting the solution on this thread, once you figure it out.
You can check out this example: Option to define custom color schemes - #2 by janis.vitums
After creating subdirectories in the Jira-home folder for the first time, we recommend disabling/enabling eazyBI app from th Jira admin page to apply for changes.
Martins / eazyBI