code: function changeColorTheme(configName, e) {
      if (e && e instanceof Event) {
        e.preventDefault();
      }
  
      var $book = gitbook.state.$book;
  
      // Remove currently applied color theme
      if (fontState.theme !== 0)
        $book.removeClass("color-theme-" + fontState.theme);
  
      // Set new color theme
      var themeId = getThemeId(configName);
      fontState.theme = themeId;
      if (fontState.theme !== 0) $book.addClass("color-theme-" + fontState.theme);
  
      saveFontSettings();
    }
docs: Change type of color theme