I Sent an iMessage to an iOS device and it appeared green instead of blue. Why?
iPad Air, iOS 8.1.3
Posted on Jan 30, 2015 8:19 PM
Q: iMessage appeared green instead of blue
You used SMS (your iPhone's text messaging).
This is explained in the HT201287 article you attached above in the section: "How do I know if my message used SMS/MMS or iMessage?".