Please add icons indicating files found in the OpenDocument format.
A sample image and more samples:
Images and masks which might be useful in creating the icon(s):
Those themes above can be used, but really any unique identifier would work.
Distros like Ubuntu now include documents in that format.
Many applications now support OpenDocument fully or on the way to full support:
The EU and many member states are now moving to using the format, so it would help clarify things to identify ODF spreadsheets, ODF wordprocessing documents, ODF database, and so on.