I actually A/B tested the impact of a light vs a dark design on the number of searches folks made and the difference was negligible [1]. Agreed through that the default order is something that can be optimized and tested going forward.

[1] http://www.mattmazur.com/2012/02/ab-testing-a-light-vs-dark-...

Love the site, but I'd agree that white on black is hard to read (and so is the green).

A toggle option to change the color scheme (since they convert about the same) would be really cool.

That said, it's your project - do what you want with it! Keep up the good work.