How to set node icons like this👇👇👇

Hi,

I believe you have to add code in the extra.less file but to confirm and I don't really know what code to put.
I had seen a resource on it on XENFORO but accessible only to those who have a license so..

If anyone can help?

Thanks !

EDIT : It's already functionnal ! In fact if new message = background color ! no new message = no background !
Test with an another account

Problem solved