From theme options – Property page settings you set default settings for all properties.

You can control also if wish to Crop Images on lightbox

Lightbox preview on property page (shows when clicking on an image in property slider)

Custom css for lightbox:

To change the lightbox background color and arrows colors you can use this custom css

.owl-carousel .owl-wrapper-outer {
background: #ffffff;
}

.owl-theme .owl-controls .owl-buttons div{
color: #da4176;
}

.owl-carousel .owl-item .item {
    background-color: #fff;
}