How to make a full-width background option in visual composer

I'm using X-Theme with Visual Composer 4.6.2 and I'm trying to create a divider layer that goes the full width of the screen like in this mock-up (the blue bar in between the content):

However, all that VC will let me do is go as wide as its container. I've used this on other, pre-fab themes before, but I don't know how to do this. I tried using revslider and a regular img, but neither work. Any ideas?

This is the dev site this is currently on.

via Chebli Mohamed