Does this sound like my number has been blocked?

It's an ex thing… But anyway, he has an iPhone and I use to text him and it would be blue. And the next day I texted him and it turned green and would never turn blue and my phone wouldn't even pick up iMessage from his side. And now every time I try to text him it's green. Have I been blocked?

You have no way of telling based on that.

Yes since iphones are all the same they all have a internetworked system and since their the same they communicate easily so most likely yes.