what do these swing color names mean

Some of the names are clear, like background, foreground, focus etc. But some are just confusing, like light, hightlight, shadow, darkshardow etc. I noticed that these are consistently used in swing UI, so I infer these are part of java's jargon. Does any body know if there is a document out there that explains these names ?

RadioButton.background  
RadioButton.darkShadow  
RadioButton.disabledText    
RadioButton.focus           
RadioButton.foreground  
RadioButton.highlight   
RadioButton.light           
RadioButton.select          
RadioButton.shadow

Solution

These are UIResource elements related to JRadionButton. Each Look & Feel provides different radio button appearance, and may set different defaults for these elements. It is also to up to L&F implementation to use these keys or not.

For example, here is a method from javax.swing.plaf.basic.BasicBorders that uses RadioButton.light and RadioButton.highlight:

public static Border getRadioButtonBorder() {
UIDefaults table = UIManager.getLookAndFeelDefaults();
Border radioButtonBorder = new BorderUIResource.CompoundBorderUIResource(
           new BasicBorders.RadioButtonBorder(
                   table.getColor("RadioButton.shadow"),
                                       table.getColor("RadioButton.darkShadow"),
                                       table.getColor("RadioButton.light"),
                                       table.getColor("RadioButton.highlight")),
                     new MarginBorder());
return radioButtonBorder;
}

However, it is may not be used by concrete L&F implementations.

PS: UIManager Defaults by @camickr can be handy to visualize different keys.