A colleague recently created a number of modules and pages and used colour coded emojis to better distinguish categories. They worked well for a while in Chrome but are now greyed out. She opened the modules in Edge and it worked for a while until again the emjois went grey.

See the attachment. The first topic's circles are green and the second are red.

This has now happened to a number of people. Any ideas brains trust?? 

Thank you!