Using an External Styles Definition File

CKEDITOR.editorConfig = function( config )
{
   // Define changes to default configuration here. For example:
   // config.language = 'fr';
   // config.uiColor = '#AADC6E';

   config.stylesSet = 'my_styles:/var/www/html/drupal6/sites/domain.com/libraries/plugins/styles/styles/mystyles.js';
};

CKEDITOR.stylesSet.add( 'my_styles',
[
    // Block-level styles
    { name : 'test', element : 'h2', styles : { 'color' : 'Blue' } },

 
    // Inline styles
    { name : 'test', element : 'span', attributes : { 'class' : 'my_style' } },

]);