silverstripe-webpack/app/client/src/scss/_typography.scss

h1, h2, h3, h4, h5, h6,
.h1, .h2, .h3, .h4, .h5, .h6 {
    color: $dark;
}

.bg-dark {
	h1, h2, h3, h4, h5, h6,
	.h1, .h2, .h3, .h4, .h5, .h6,
	.typography,
	a {
	    color: $white;
	}
}

.typography {
    @import "./types/editor";
}