Radio button labels are not displayed in Service Portal

A catalog item was created with a "Numeric scale" type variable. 

The radio button labels are not displayed in Service Portal.   

The labels are visibles in the UI Platform. 

Inspect the page and you will see the labels are displayed but the font color is white and the background color is white, so the labels are not visible. 

1. Go to the Service Portal >> Portals 
2. Edit the service portal in question 
3. Go to the "CSS variables" section, you will see the following line:
   $text-color:#ffffff;
   
   Change to a different color, for example:
   $text-color: #717171;  
4. Save

The issue will be fixed after this.