Apple uses different colored message bubbles to indicate whether a message is sent via iMessage (blue) or standard SMS/MMS (green).
The Apple iPhone, by default sends messages addressed to multiple recipients as MMS messages. When a message is addressed to multiple recipients, the message is sent via MMS and iPhone header displays, "New Group MMS".
The steps below apply to the following models:
iPhone X / XS / XS Max / XR
iPhone 8 / 8 Plus
iPhone 7 / 7 Plus
iPhone 6 / 6 Plus / 6s / 6s Plus
iPhone 5 / 5c / 5s
iPhone 4 / 4s
From the Home screen, navigate: Settings > Messages .
Tap the MMS Messaging switch (may require scrolling down) to turn on or off .