Hello @Alankrit_Choudh . Thanks for the feedback.
Firefox does not support the background-clip: text required by this the rainbow tag.
I will update the documentation and provided some graceful degradation for unsupported browsers.
Also, I need to document that it’s now possible to define custom “typeface” tags in the Admin settings, and customize the end result via site CSS customization:
.typefaces-tag.<tagname>{
// css properties
}