On Android devices, the color of the message bubbles within the default messaging application often signifies the technology used to transmit the message. Blue bubbles typically indicate that the message was sent and received using Rich Communication Services (RCS) or Advanced Messaging. For instance, if both the sender and recipient are using Android devices with RCS enabled, messages exchanged between them will likely appear in blue bubbles.
The use of this color to represent a specific messaging protocol offers benefits such as improved features and functionality. RCS supports higher quality media sharing, read receipts, typing indicators, and larger file transfer sizes compared to older SMS/MMS protocols. This transition represents an evolution in mobile communication, bringing features previously exclusive to other messaging platforms to the standard Android messaging experience.