7.1 - Banner Overlay Opacity

Under colors > sitewide > background overlay I can set the color to black, but is there anyway to make the overlay darker?

I need something like:

background: rgba(0, 0, 0, 0.7)

And cannot find the element to change in inspector tool. This functionality existed with 7.0 iirc.

change 0.7 (0 > 1)

The class is:

.section-background-overlay {
    opacity: 0.125;
}

So you can make the opacity value closer to one to get more of the overlay color.