Hi all!
I managed to use these contextual labels with the help of Dr. Vered Shwartz.
Here is how she told me:
I used the default bootstrap labels: https://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_labels2&stacked=h, and added a few of my own to the CSS, for example:
.label-short { background-color: #d27979; }
And then in the HTML: short
Thanks Vered! Yisong