colored area/line on homepage

Hi Sakin, Could you please help me out again? On our homepage: http://www.egyptologie.nl/Boekenverkoop/ below the 4 featured content items, and above the footer widgets, you can see a dark gray / blackish area/line. I want to remove that, but I don't know what that line is. Is it something I can disable within the theme options? Or do I have to add some code? If I didn't explain clear enough, please let me know.