I have styled some progress bars by applying classes to them and using this scss
.widget-progress-bar.progress-distance-ahead .progress-bar {
background-color: $brand-success;
}
.widget-progress-bar.progress-distance-behind .progress-bar {
background-color: $brand-danger;
}
.progress-distance-behind > .progress {
background-color: $brand-danger-background;
width:$progress-size;
}
.progress-distance-ahead > .progress {
background-color: $brand-success-background;
width:$progress-size;
}