CSS font color bug on error rows

The CSS file for this module needs an addition to the last two rules in order to avoid a situation where font color is unknown. The default CSS file sets the background of the tables cells to a very light color. In a site which had already specified body{color:#fff;}, this would result in an unreadable page.

I've attached a modified version of the file which specs black as the default font color for the tr.error and the tr.ok table rows.