Seems to me two things are being discussed here:
1) voice inflection and emotes as part of a say or tell
2) color changes within a say or tell
First off, I'm all for voice inflection being part of a say or tell, to a certain point. Example:
X says '*in a gravely voice* Good morning.'
is a lot different than
X says '*in a gravely voice as he looks disgustedly at Y* Good morning.'
Vocal tone is one thing, adding action to it is just skating around putting in an emote.
As for color changes in says and tells, If it's only one color, and the whole line is that color, or it's being used for emphasis, great. Some people (Mezcao...) should be shot for the sheer amount of crap they put in front of what they say. A simple *darkly* or *speaking in a deep voice* would get the point across, or even putting the whole line in dark gray.
In closing -
$0 should be removed from the mud entirely, to be replaced by light and dark grey.