I read on dojocampus.org that the color of the Dialog’s underlay can be changed. The example on the site shows how to change the underlay color of an individual dialog box:

    #dialogColor_underlay {
        background-color:green;
    }

<div id="dialogColor" title="Colorful" dojoType="dijit.Dialog">
     My background color is Green
</div>

But, this only changes the underlay color of an individual dialog box. It seems to me that unless I am building an Dojo application for, let’s say a kid’s website, that I want the color change to be consistent. I also don’t want to have to create a separate style for each Dialog box that I may have on a page. So, to change the underlay color for all dialog boxes on a page:

.dijitDialogUnderlay {
     background: green;
}

Easy.