Hello Jesse,
Thanks for writing in!
If you only want to change background color of Review box, please add following CSS under X > Theme Options > CSS:
.reviews_pane.active {
background-color: #ECECEC;
margin-top: 10px;
border-radius: 20px;
}
In case you also want to change background color of Description area, please add following CSS under X > Theme options > CSS:
.description_pane.active{
background-color: #ECECEC;
margin-top: 10px;
border-radius: 20px;
}
In above code margin-top: 10px;
and border-radius: 20px;
is optional that I added to style the background color. You can remove the same as per your requirement.
1- I have found the proper CSS code selector using the Chrome browser Developer Toolbar: https://www.youtube.com/watch?v=wcFnnxfA70g
2- For the CSS code itself, I suggest that you get started with this tutorial: https://www.youtube.com/watch?v=yfoY53QXEnI
Thanks.