Css class visible in tinymce Styles dropdown

I have followed every tutorial I could find on inserting my own custom classes in the TinyMCE Styles dropdown.

I have successfully made visible the Styles dropdown and incorporated my class within it.

However, I cannot for the life of me figure out how to make the class in the dropdown be 'colored' the way my class requires it to be. For instance in a dropdown if the css class is color:red, I would want that to appear in this way within the style dropdown. Unfortunately, it's always black so the user doesn't get a visual cue on what effect this class will have on the text.

For instance, see this screenshot: http://compumatter.com/styles_dropdown.png I want to have the class 'cm_38px_teal_times_ital' be actually a 38px teal colored selection.

I have tried:
add_action( 'admin_init', 'add_my_editor_style' );

function add_my_editor_style() {

which based on readings seemed to indicate this was the way to incorporate rendering of the actual class effects but this has failed.

Has anyone out there got experience with this one ?

I am using no added plugins for TinyMCE other than the core functionality. Just an FYI for you.

What sayeth the group ?