Background color in mobile version of theme

Hi all,

I’m currently running Dynamic News Lite and have selected a black background for my website. All looks well on the desktop version, but the site background is still showing as white on the mobile and tablet versions (have used MobileTest.Me to try it on a few different systems). Is there an easy fix for this issue?

Note: the header and post backgrounds etc. are responding fine. It’s the actual page background selected through Dashboard > Appearance > Background that is troubling me.

(Crossposted from Troubleshooting)