"..." in a gray bubble on the iPhone Message screen, and message color?

On the iPhone [text] Message screen, only when I text another iPhone, occasionally a gray bubble comes up saying "..." I know it's probably obvious yet I just have never been told. I believe it means either they're typing a text to me or it is being delivered by them to me. Also, why are some... show more On the iPhone [text] Message screen, only when I text another iPhone, occasionally a gray bubble comes up saying "..." I know it's probably obvious yet I just have never been told. I believe it means either they're typing a text to me or it is being delivered by them to me.

Also, why are some of my texter's texts blue and some green?

Thanks.
4 answers 4