"class" property setting on column not pulling in styles from .scss file

When using the "class" property for a specific column, the referenced styles found within my component's scss file are not being applied. Inside the browser's developer tools I can see the class being applied to the correct column header, but no styles. Is this a bug? Or am I missing something?

Component (inside settings.column):
x: {
title: 'X',
class: 'min-width'
},

In component's SCSS file:
.min-width {
background-color: red;
}

Referencing SCSS file in component via:
styleUrls: ['./foo.scss'],