Aalborg Theme logon background color

Hello there.  I'm having difficulty understanding how to make what I thought was a simple change: The logon screen background color.

I've installed Elgg 1.10 (brand new site).
Copied the Aalborg theme into a new custom plugin and have made no further changes.
Enabled the Walled Garden.

Any place I think it would make sense to make the change doesn't seem to work.  And I have flushed the caches.

If anyone has successfully made this change, please let me know.  I have other plans for the login page, but if I can't even change the background then I'm going to get nowhere.

Any assistance would be greatly appreciated.

 

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Beginning Developers

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