Customising a GUI Slider?

Hey guys,

I've read through the entire GUI scripting guide several times and tried looking through the documentation and this site itself, but I cannot find how to change the colour of a simple

GUI.HorizontalSlider(Rect(A,B,C,D),sliderValue,0.0,1.0));

Sure, exposing the GUIStyle var opens op a lot of options, but all of them seem to mainly have to do with buttons. What I simply need is to change the color of the bar and the tab. And preferably also be able to change it through scripting, for instance:

if(sliderValue <= 0.01) {
    //change colour to a little more darkish
}

It's most likely something really simple I've overlooked, but god knows I've tried. Many thanks in advance for trying to help! :)

Have you tried backgroundColor ?

GUI.backgroundColor=Color.red;
GUI.HorizontalSlider(Rect(A,B,C,D),sliderValue,0.0,1.0));