Function for updating iframe CSS

[KoulSlou]

I faced with a problem when I add new CSS class to textarea element, but iframe style is not changing at all.

For example, I add class:

.not-saved{
    background-color: black;
}

But editor's background stays white. My questions are:

1). Is there any function for synchronization of textarea and iframe styles?
2). For some reason I can not change inline properties set in editor's iframe even with jQuery function:

  $(jqObject).parent().find("iframe").css({'background-color': '#000000'});

It's still white.

Would appreciate any help.