IMessage turned from blue to green, did I get blocked?

I sent a message from my iPhone To my friend who also has an iPhone, and texts between us are always blue, this time when I texted him it was blue as usual after like 3 min I opened the message again to find it green ( sent as a text) did he block me! Is there another way to know without trying to call him? Maybe sending another follow up message will help me figure out, if he blocked me or not, thanks in advance.

If you turn iMessage off in the settings it turns the text back to green like as if you were using an android. They either turned it off or you were in a spot with little service connection. Happens to me all the time.

No, if it just means the recipient turned their iMessage off so was sent as a regular SMS

I read If the text is blue but does not say 'delivered' then you are blocked. However, I also read online that three minute color change can indicate you were blocked:/