code: public void configureColor(AbstractButton button) {
          Assert.notNull(button, "button");
          if (foreground != null) {
          	button.setForeground(foreground);
          }
          if (background != null) {
          	button.setBackground(background);
          }
      }
docs: Configures the given button with colours for background and foreground if available.
  
  @param button The button to be configured. Must not be null.