Hi,
I’ve inspected your site and found that the background-color for the hovered zoomed images are still white (#fff).
.woocommerce div.product div.images .woocommerce-product-gallery__wrapper .zoomImg {
background-color: #fff;
}
Perhaps what you meant was the popup modal when you click the magnifying glass icon?
If so, you can try adding this CSS:
.pswp__bg{
background: #FFF !important;
}
A wise man once said:
"Have you cleared your cache?"