Preload Background Image

I’m having trouble with the preloader background color. It’s currently flashing a white box when the site first loads and I’m wanting that to be transparent.

I’m using this currently:

.easingslider .easingslider-slide .easingslider-preload {
background: transparent !important;
background-color: transparent !important;

And it used to work, but it doesn’t seem to anymore. Am I missing something? Thanks!

https://www.ads-software.com/plugins/easing-slider/