Simplest solution is to install the Simple CSS plugin:
https://en-gb.wordpress.org/plugins/simple-css/
In the post/page editor you will see a Simple CSS meta box, anything you add here will only apply to that page. And you would add this CSS to set its background to white:
body {
background-color: #fff;
}
Alternatively you would have to write page specific CSS eg.
page-id-36,
.page-id-38 {
background-color: #fff;
}
You home page ID is 36, your About is 38. You can get the ID from the post editor by checking the URL. Simply add more comma separated CSS selectors to that CSS rule.