web part not picking up style changes

I added a content editor web part to my page (as suggested for OOTB web part styles) and the web part I'm trying to add the styles to isn't picking it up. I pulling the Web part title in the css and nothing, I have the content editor hidden=true so it doesn't show up on the screen to the users.

Am I missing a step here?

I have this CSS in the content editor:

<style type="text/css">

#WebPartTitleWPQ2 h2

{ background:gray !important;}

</style>