I sent a text and it went green as "Sent as Text Message" on my iPhone. And it says "Delivered" on my Mac, both showing different things. (I sent the text originally from iPhone, went blue then green). Does that mean I am blocked?

iMessage (Blue) -

• iPhone to iPhone: requires internet (Either over WiFi or Cellular Service) as it is sent over internet protocol. Needs Activation on your device.
• iPhone to Android: Not available

SMS/MMS (Green) -

• iPhone to Android: does not require any internet it is sent over cellular voice protocol. Needs to be enabled by your Carrier for the SIM used by you.
• iPhone to iPhone: When iMessage is not activated or the device is not connected to the internet either over cellular or WiFi

It will turn from Blue to Green if you have enabled "Send as SMS" and whenever your iPhone is not connected to the internet it is sent as SMS (green) to all iPhone users.

You will never know for sure when someone blocks you. You may make many guesses that will not yield an answer.