While trying the graphics settings recommended by Gorgeous Yongho in "How to Take & Publish a Gorgeous SL Fashion Screenshot," a blog post by Hamlet Au, I found that activating the Lighting and Shadows feature in my viewer Graphics Preferences completely borks the picture.
|Before activating Lighting and Shadows|
|After activating Lighting and Shadows|
Maybe in the next version or two of the Official Viewer or Kirstens, the two viewers I tried, will iron out this problem. But other than changing to a Windows machine or going back to OS X 10.6, feel free to post any ideas you have.