What's with different chat bubbles on the S8?

[Android Central Question]

When I text my best friend, our chats show up green with read receipts but when texting my fiancé (and anyone else for that matter), it shows up yellow. Both my friend and fiancé have the same phone, same provider and we can't seem to figure it out anywhere online. Our settings are also all the same on all phones.

 

[Tim1954]

Favourites? Are they all in /not in favourites?