look and feel meaning code example

Example: Look and Feel

private final void customizeNimbusLaF() {       
    UIManager.put( "control" , UIConstants.GREY_LIGHT );
    UIManager.put( "nimbusAlertYellow" , UIConstants.YELLOW );
    UIManager.put( "nimbusBase" , UIConstants.GREY_DARK );
    UIManager.put( "nimbusDisabledText" , UIConstants.GREY_DARK );
    UIManager.put( "nimbusFocus" , UIConstants.BLUE_LIGHT );
    UIManager.put( "nimbusGreen" , UIConstants.GREEN );
    UIManager.put( "nimbusInfoBlue" , UIConstants.BLUE_MIDDLE );
    UIManager.put( "nimbusRed", UIConstants.RED );
    UIManager.put( "nimbusSelectionBackground",
    UIConstants.BLUE_MIDDLE );

    UIManager.put( "background" ,UIConstants.GREY_LIGHT );
    UIManager.put( "controlDkShadow" , UIConstants.GREY_DARK );
    UIManager.put( "controlShadow", UIConstants.GREY_MIDDLE );
    UIManager.put( "desktop", UIConstants.BLUE_MIDDLE );
    UIManager.put( "menu", UIConstants.GREY_LIGHT );
    UIManager.put( "nimbusBorder", UIConstants.GREY_MIDDLE );
    UIManager.put( "nimbusSelection", UIConstants.BLUE_MIDDLE );
    UIManager.put( "textBackground", UIConstants.BLUE_LIGHT );
    UIManager.put( "textHighlight", UIConstants.BLUE_LIGHT );
    UIManager.put( "textInactiveText", UIConstants.GREY_MIDDLE );

    // panel
    UIManager.put( "Panel.background", UIConstants.GREY_LIGHT );
    UIManager.put( "Panel.disabled", UIConstants.GREY_LIGHT );
    UIManager.put( "Panel.font", UIConstants.DEFAULT_FONT );
    UIManager.put( "Panel.opaque", true );

    // button
    UIManager.put( "Button.background", UIConstants.GREY_LIGHT );
    UIManager.put( "Button.disabled", UIConstants.GREY_LIGHT );
    UIManager.put( "Button.disabledText", UIConstants.BLUE_MIDDLE );
    UIManager.put( "Button.font", UIConstants.DEFAULT_FONT );

    // menu
    UIManager.put( "Menu.background", UIConstants.GREY_LIGHT );
    UIManager.put( "Menu.disabled", UIConstants.GREY_LIGHT );
    UIManager.put( "Menu.disabledText", UIConstants.GREY_DARK );
    UIManager.put( "Menu.font", UIConstants.MENU_FONT );
    UIManager.put( "Menu.foreground", UIConstants.BLACK );
    UIManager.put( "Menu[Disabled].textForeground",
            UIConstants.GREY_MIDDLE );
    UIManager.put( "Menu[Enabled].textForeground", UIConstants.BLACK );
    UIManager.put( "MenuBar.background", UIConstants.GREY_LIGHT );
    UIManager.put( "MenuBar.disabled", UIConstants.GREY_LIGHT );
    UIManager.put( "MenuBar.font", UIConstants.MENU_FONT );
    UIManager.put( "MenuBar:Menu[Disabled].textForeground",
            UIConstants.GREY_MIDDLE );
    UIManager.put( "MenuBar:Menu[Enabled].textForeground",
            UIConstants.BLACK );
    UIManager.put( "MenuItem.background", UIConstants.GREY_LIGHT );
    UIManager.put( "MenuItem.disabled", UIConstants.GREY_LIGHT );
    UIManager.put( "MenuItem.disabledText", UIConstants.GREY_MIDDLE );
    UIManager.put( "MenuItem.font", UIConstants.MENU_FONT );
    UIManager.put( "MenuItem.foreground", UIConstants.BLACK );
    UIManager.put( "MenuItem[Disabled].textForeground",
            UIConstants.GREY_MIDDLE );
    UIManager.put( "MenuItem[Enabled].textForeground",
            UIConstants.BLACK );

    // tree
    UIManager.put( "Tree.background", UIConstants.BLACK );      
}