this is a really simple background template for octomoosey’s Theme 45. i checked here to make sure it would work on different screen resolutions and it should, but use that after you make your bg just to be sure!
when editing the actual theme, in the simple customization area, make sure the background color matches whatever you use on this template. you can google the RGB (red, green, blue) value - like google search “rgb (51, 102, 204)” to find the right hex code for it, which you can paste into the color selection rather than clicking around trying to match it.
i’m not a master of container themes or anything... but this should make it a little easier, at least for this particular theme. if for any reason this template violates octomoosey’s rules (which i don’t think it does?? i checked his faq and everything), then i’ll remove it.
enjoy!