Do HTML/CSS/JavaScript define constants representing system theme colours? I mean those colours a user can define in the operating system (or a browser) control panel. Like standard window contents background and text colours etc.
The idea is to make a web site to respect the user preferences by default, showing light text on dark background in case the user uses such a theme in his system (while following the Occam’s razor principle by avoiding introducing extra configuration).
Yes you can,
Open firebug and change some css declaration like color : ActiveBorder or see webdesign.about.com/od/colorcharts/l/blsystemcolors.htm or search the net for ‘css system colors’
For a better reference suggested by unor about system colors