3 issues in IE [footer columns, menu position, background color]

My site is https://tedxnottingham.org
U: tedxnott
P: tedxnott

I’m using the photoria theme (https://www.wpzoom.com/themes/photoria/) and here’s an example site (https://fridayfavorites.com/).
Both the demo and examples work fine with the theme in IE, but my site is having problems. Issues I current have:
– Background colour is off
– Menus refuse to appear (they did at first but very horribly off to the right side)
– 4-column footer is only 3 columns in IE so that the fourth ends up being rendered under the 3rd instead of next to it.

Would love some assistance on this one, thanks!