...which suggests that the notion that some designer at Apple subtly decreased the contrast on green bubbles to make them look "gross" is ridiculous -- if they really wanted to make SMS messages look bad, they could be much less subtle about it...
They have to be very, very subtle, and ride the fine line between effectiveness and outrage, never going too much on a side or the other. The best and most enduring conspiration theories have originated from such deliberate and surgical manipulations. The goal they are after: most people will unknowingly abide and be manipulated, while the minority will go nuts proclaiming they know the truth.
Welcome to propaganda 101, aka destructive marketing.