CSS not updating with aggregation turned off
Your CSS file may still be being cached, even if not aggregated.
You can refresh the ?oegwy2 querystring with drush 

drush cc css-js


Which refreshes the config variable: css_js_query_string

You could also add the following to your dev env settings.php to disable that querystring var:

$conf['css_js_query_string'] = '';


Then you should be able to just use hard reload (e.g Shift+Refresh) to refresh the CSS.