webpack-bootstrap-ui-kit/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 {
    @include clearfix;

    @import "./types/editor";

    > *:last-child {
        margin-bottom: 0;
    }
}