> save the green vs. blue bubbles, which are in their own way a sort of weird social/status indicator
Save your opinionated anti Apple rhetoric. The color coded indicator allows people to know which features are included in the service, or whether your text was delivered and read or in your case, not delivered...
While color coding totally serves a useful purpose, it's also DEFINITELY used by some as a indicator of status or inclusion in a group. People are super tribal, and will use any indicators available to indicate inclusion or exclusion.
iMessage uses shading based on transport (SMS/MMS vs. iMessage) for both your messages and others, but from looking at my own mixed SMS/MMS/Hangouts threads, Google uses green for your outbound messages sent with Hangouts, and grey for your outbound SMS/MMS messages and all incoming messages (with "via SMS" and "via MMS" alongside the time display on in- and out-bound SMS/MMS messages.)
So, to the extent that the Apple behavior can be seen as signalling in-group membership with color of messages, it is distinctly different from Google Hangouts, since the only person whose messages are colored to indicate delivery method in Hangouts are yours, not the ones you receive from others.
I would find it VERY surprising if those colour choices were purely accidental, wouldn't you?
On iOS, messages were always green, until the introduction of iMessages. The blue colour is therefore associated with newness. Like when you open a skeuomorphic iOS 6 app and no matter if you like the interface or not it's associated with an older.. dare I say "dated" look and feel.
On Android I don't know the history, but I do know that grey is definitely less vibrant than green... grey is dull, faded, old, etc.
I mean, we can argue about the size of the impact of these choices, but you must agree there was some intention to them.
Save your opinionated anti Apple rhetoric. The color coded indicator allows people to know which features are included in the service, or whether your text was delivered and read or in your case, not delivered...