HTML helper: adding classes to li using ul()

[eluser]stef25[/eluser]
I'm using the HTML helper to print out the main navigation of my site in an unordered list. Is there any way I can add a class="active" to a list item?

If

Code:

$this->uri->segment(2) == "red"

I'd like to add class="active" to the html output for that element.

Code:

$list = array(
            'red',
            'blue',
            'green',
            'yellow'
            );