You may have noticed that the text messages in your iPhone's Messages app can appear as either green or blue. The difference? Green messages are ordinary SMS text messages, while blue messages are using Apple's proprietary iMessage format.
For green messages, the texts that are sent are compatible with a wider range of phones and receiving services than blue iMessage texts. Since Android and other carriers operate within the SMS and MMS standards of text communication, these green texts are more versatile in who they can reach with their texts.
Your old messages remain blue, but the latest texts you send after they've blocked you turn green. However, the bubble colors aren't accurate clues. They could mean the recipient turned off their phone, gone offline, or switched from iOS to Android.
If you see a green message bubble instead of a blue one, then that message was sent using MMS/SMS instead of iMessage. There are several reasons for this: The person that you sent the message to doesn't have an Apple device. iMessage is turned off on your device or on your recipient's device.
If your iPhone messages are green, it means they're being sent as SMS texts rather than iMessages. You'll always see green when texting Android users, or when you're not connected to the internet. If all of your iPhone messages are green, you should make sure iMessage is turned on in Settings.
A green text message on your iPhone isn't a sign that your phone number was blocked, or that the text was not delivered. Instead, it means that the message was sent as a standard SMS message rather than an iMessage, which will appear as blue.
The Recipient Wasn't Using an Apple Device at the Time
Remember, iMessage only works between Apple devices. So, if your family or friend switches from an iPhone to an Android smartphone, for example, your iMessage will automatically be sent as a text message to them.
The Recipient Has Changed the Phone
iMessage service is only available on Apple's hardware lineup, including iPhone, iPad, and Mac. If the recipient has changed their primary phone to Android, messages turn green on iPhone.
Instead, a green text message on an iPhone is an SMS message that has been delivered to a phone that is not an iPhone or Apple device (ie. an Android). A green message can also mean that you aren't connected to the internet or that your iMessage is turned off in settings.
Check the Bubble Color
If you don't see a blue bubble on your end, then it's likely that they've blocked you on iMessage. It's important to note that this doesn't mean they have blocked your number altogether; it just means they have blocked you from sending them messages over iMessage.
This is the way Android Messages indicates whether the message is being sent via RCS or SMS/MMS protocols. The darker messages are RCS.
The green message background indicates the traditional SMS text message. It actually means a message that you have sent to someone else is through SMS message service instead of Apple iMessage. Blue message background means the message is sent via iMessage technology.
Send them an SMS message
When you send them an SMS and you get the "Delivered" notification underneath it, you weren't blocked. If you get a notification like "Message Not Delivered" or you get no notification at all, that's a sign of a potential block.
Check Your Spam & Blocked Folder
If you use Truecaller or any other Android app for SMS messaging, check their respective guides to find out where they store spam or blocked messages. If you're not receiving a message from a specific contact, you may have blocked their number.
If you send a message as a regular SMS in the green text bubble and you do not get a “Delivered” notification but instead get a notification similar to “Message not Delivered” or no message at all, that means you were probably blocked.
SMS is available on virtually every phone and tablet in the world. iMessage on the other hand is available only on Apple devices. But one of the major differences and in fact, the most important is security. iMessage texts contain a thing called end-to-end encryption that regular SMS texts don't.
When you're blocked on iMessage, Apple's messaging service prevents your instant messages from getting delivered to the person you're trying to reach. If you have text message fallback enabled, your device will resort to sending the message as a text, meaning the bubble will turn green after someone blocks you.
So if the recipient is using an Android device, for example, you'll receive a “sent as text message” confirmation, and the message will appear in a green bubble instead of blue.
“The last message that you know was received and responded to…should have a 'delivered' status,” Lavelle explains. If, under the messages you've sent after that, you don't see that “delivered” notification, that could mean that person has blocked you.
You can tell if your message has been sent via iMessage in Apple's messaging app because it'll be blue. If it's green, it's an ordinary text message and doesn't offer the read/delivered receipts. iMessage only works when you're sending messages to other iPhone users using the Messages app.
In that case, you may not get the “Delivered” tag if you message them, but the message bubbles will be blue. To bypass this: Tap and hold the message you sent (if it says “Not Delivered,” tap the little exclamation mark next to it).
Which is better for you? Most iPhone users will want to use iMessages, so long as they have a good plan that can handle the data usage. The only reason to use SMS instead of iMessage is if you're chatting with people who don't have Apple devices, or if you don't have any data on your phone.