Change the background color and text color of the lightbox.

If you would like a dark background instead of the white background for the lightbox. Use this CSS to make the text white and choose a background color.

CSS

.sbi_lb-dataContainer {
background: #33c6a7 !important;
}
.sbi_lb-caption,
.sbi_lightbox_username p,
.sbi_lightbox_action a,
.sbi_lb-number,
.sbi_lb-comment-text {
color: #fff !important;
}
.sbi_lb-caption a,
.sbi_lb-comment-text a,
.sbi_lb-commenter {
color: #ccc !important;
}

The red text is the hex number of links in the lightbox.

The yellow text is the hex number of the background color you would like the lightbox to be.