You would better create an attribute and show its label on the product. You will find this option in the product attribute. Then if you need we can customize with CSS as per your needs.
Please add this code to the Theme Settings > Custom CSS > Global:
body .labels-rectangular .product-label.label-term-precio-web{
background-color:red;
color:yellow;
}
I cannot move this separate label to the right, HTML structure does not allow doing that with CSS. I can move all the labels to the right, please let me know if you need this.
Please replace the red color with yours as I cannot catch this semi-transparen color.