Samsung S20 blue text bubble turned to green after sending

[Niques]

Hi,

I have a Samsung S20 and I recently sent a friend text which was initially blue and then minutes later turned green. No delivery notice given. What does a green bubble mean? How can I turn this to a blue bubble text so that the message is delivered? It only happens to this one friend. He is using a Samsung phone. 

Thanks

[BandOfBrothers]

A green bubble indicates the message is sent from the Samsung Texting App.

A blue bubble means it's converted into a rich text message i.e advanced messaging app / Rcs messaging.

See this similar thread Galaxy-s21-series/text-bubbles. 

And some information in https://samsungtechwin.com/what-do-blue-text-messages-mean-samsung/ 

I personally disable the rich messaging app @Niques 

[Hellyj]

Can you help. I have the Samsung S20 fe. The colour of the text bubble when I reply is normally a dark maroon colour, but it sometimes it goes to a bright orange colour. What does it mean. Will it affect the text message I send. Thanks