Why would I want to put my logo in a white box?
Some logos don’t look that great against Basecamp’s grey sidebar. If your logo works better against a white background, you can place it inside a white box instead. Just click the “Settings” tab and select the checkbox next to your logo that says, “Put the logo in a white box.”
If you’re trying to match the grey Basecamp background color, use #E5E5E5.