I discovered this little gem of a cartoon while researching infographics. It's mostly whimsical with a lot of truth-guys do see colors differently. The cartoon is free to share under the creative commons licensing (see below). I suspect you could use it in a gender/perception portion of a unit. If you go through their collection, many of the cartoons are gender and relationship based. Enjoy.
The original site is: http://thedoghousediaries.com/
From their site:
Our comics are licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License
posted by Chuck Schallhorn