Changing a stickied .excerpt-container's color?

Hi again, Ben.

When posts are stickied, the excerpt container has a yellow/beige color. I would like to change it. The closest I got was changing the background behind the featured image, with

.sticky {
background: white;
}

Variations of that, e.g.

.sticky .excerpt-container {
background: white;
}

seem to do nothing. What am I missing?