add the module suffixes "nopaddingall" and "nomarginall"; no quotes, a single space between them...
more module suffixes can be found at the bottom of this page:
The Header in Vermilion has a fixed bottom margin to accomodate the logo... you can kill that with custom css:
This is how to create a custom CSS override file compatible with Gantry 4...
Simply create a file called "<TEMPLATENAME>-custom.css" and put this file in the CSS folder of the template (where <TEMPLATENAME> is the name of the template as seen in template manager e.g. rt_vermilion). GANTRY4 will automatically load this CSS file. If you wish, you can also have browser specific files by appending, for example, "-ie9" making the filename "<TEMPLATENAME>-custom-ie9.css"
Even more here: