Why are some of my texts green and others blue on iPhone? Does green mean something bad?

Relax, green does not mean you're blocked. Blue bubbles are iMessage, sent between two Apple devices over the internet. Green bubbles are regular SMS/MMS, which is what iPhone falls back to when you message an Android phone, or when iMessage can't connect. So a green bubble almost always just means that person is on Android, or you briefly had no internet. Being blocked doesn't change your bubble colour, your messages just quietly don't arrive.

Green = the other person is on Android, basically every time. The blocked myth needs to die. If you're blocked, the colour doesn't change, the message just never gets delivered.

It can also go green if your own iMessage is glitching. Settings > Messages, toggle iMessage off and on, and check you have signal or wifi. Sometimes an Apple-to-Apple text turns green just because iMessage couldn't connect that second.

One more: green SMS texts aren't encrypted the way blue iMessages are, so if privacy matters, that's the real difference worth knowing, not blocking.