Content does not specify text characteristics or background color, and is not relying upon technology that changes those defaults.
The objective of this method is to make sure that users can read text that is presented over a background. With this method the author avoids having to do any contrast measures by simply not specifying the text color and not specifying the background. As a result the colors of both are completely determined by the user agent.
Some people who have vision disabilities set their user agent to override certain colors that they have trouble seeing. This method will help avoid a situation where the user agent and web site conflict with each other over the foreground and/or background colors resulting in the same color for text and background, which would make it invisible for user who set their own colors in their browser or Assistive Technology.
The author specifies neither text color nor background, and does not use CSS. As a result the user can set his browser defaults to provide the colors and contrasts that work well for them.
None. No HTML or CSS font or color styles are set.