I'm developing a jQuery Backbone.js web app.  

I have a table with table entries. The table has a white background.  

If the user selects a table entry, a modal popup is shown. To show the user that the popup is now in modal mode, I used to have the jQuery UI diagonal stripes (ui-widget-overlay). 

But I changed to an alternative. Those stripes were too "striking", "obtrusive" for me. I now change the opacity of the table to 0.5. I like this more. 

The problem now is that I have popups in the popup window. And if I also change the opacity of the first popup to show the user that only the second popup is working now, the table shines through the first popup. 

Is there any possibility, any alternative way to have a popup window (a div) "dim", "grey out" to half of its appearance without getting transparent?