Comment 4 for bug 496338

It is more legible with the color change at the size there, but when you take a look in the address bar (at least in Firefox) the letters cannot be made out--this could possibly be fixed by doing a specific version for small sizes (the dimensions are of course skewed in the address bar), but it could also be that the lettering does not scale. I am not sure.
(Sorry for criticizing without contributing)

When SVG was putting out the rules for its logo (in a contest, late 2006), it specified the following (relevant) guidelines:
* Should work well across a variety of scales and media. Some optimal suggested dimensions include:
  * 80 x 15 (small button)
  * 88 x 31 (large button)
  * 32 x 32 (icon)
  * 1000 x 1000 (T-shirt or poster)
* Should work well on a light background (e.g. for printing on white paper) or a dark background (for digital environments)
* Should degrade well to black-and-white

Full list (most others are SVG-specific and therefore not relevant):
http://web.archive.org/web/20071231022515/svglogo.com/contest.html (actual site's no longer available)