Background Color for Text

Hello,

I have been working on implementing a method for highlighting text
through the use of a rectangular, solid-fill background behind text.
Currently I have been using <rect> and some math to generate the
"highlight" behind the text. However, if there was a background-color
option for text just like in CSS this would make everything much easier
and more accurate (different font families cause my highlight scheme to
fail horribly). My application is dynamic generation of SVG images with
embedded text with the option to highlight certain text elements while
leaving other text elements unhighlighted.

Is there any method for the person writing HTML/CSS/SVG (to be viewed in
a browser/SVG viewer) to generate a background color for text without
resorting to complex algorithms and assumptions about fonts/glyphs
(technical details about which are typically are not available to the
SVG document itself)?

Thanks for your time,
Darrik