Oneboxing of site links is often not visible, especially on beta sites:
Many sites, like Ask Ubuntu and Sharepoint also have predominantly white logos in oneboxes.
These images should have a background colour, so that they are visible.
Update: adding some other information:
- chat.stackoverflow.com has a slightly off-white background, so the white content is still slightly visible. chat.stackexchange has a pure-white background, white content is gone.
the one-box for
http://stackexchange.comis pure white, and looks like:
at least on chat.stackoverflow the white is visible: