Had the following in my code. With this setup the media query was not captured setting the background color at all screen sizes, not just those under the max-width.
.element {
@media (max-width: 600px) {
&.modifier {
@include brand(brand1) {
background-color: brand-color(color2);
}
@include brand(brand1) {
background-color: brand-color(color3);
}
}
}
}