light-themes scheme, you need to include a file called copyright (or LICENSE) in
/usr/share/doc/your-theme-name that includes the complete
/usr/share/doc/light-themes/copyright file), which starts as:
Upstream Author: Kenneth Wimer
Copyright: (c) Canonical Ltd 2004- 2010
Unless otherwise indicated, artwork is available under the Creative
Commons Attribution Share-alike license v3.0 or any later version. To
view a copy of this license, visit
http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to
Creative Commons, 171 Second Street, Suite 300, San Francisco,
California, 94105, USA. See below for the full text of the license.
Some Rights Reserved:
The rights in the trademarks, logos, service marks of Canonical Ltd,
as well as the look and feel of Ubuntu, are not licensed under the
Creative Commons license and are subject to the Canonical Trademark
Policy at http://www.ubuntu.com/ubuntu/TrademarkPolicy
full CC license (see the `copyright` file)
At the beginning, include a line like
Derived from the Ubuntu light-themes package.
After the "Upstream Author", as a courtesy I would also add
Maintainers: and include the Ubuntu Light Themes Contributors, preferably with the link to their page.
If you are simply distributing this as a zip file or a patch or something, just including all the above as a
LICENSE file in the root or inline as a comment (in that case no need for the full license text, just link http://creativecommons.org/licenses/by-sa/3.0/ ).