Texts suddenly change from blue to green

To make a minor correction to sberman's post, blue indicates iMessages which require an Apple device, green indicates SMS which can be an Android phone or an Apple user who chooses not to use iMessage. It can also mean that an iMessage users does not, at the current time, have an active data connection. Or you don't. Or the person has signed out of iMessage for some reason.

Blue messages indicate iMessages sent to/from other Apple devices.

Green messages indicate SMS text messages sent to/from other cellular telephones.

It could simply be that, for some period of time, they didn't have a data connection. But yeah, ask them.

Best of luck.

IdrisSeabright, many thanks for your clarification and extra insight.

sberman wrote:

IdrisSeabright, many thanks for your clarification and extra insight.

Teamwork.