I know this topic is on "the list" and has been raised many times before.
It would be helpful (as an interim step) that if a message is output a s a warning (as opposed to info / error / debug / threaddebug) if it was coloured say ORANGE. This would highlight the warning but not at the severity of an error (RED). At the moment plugin developers have to make the decision as to whether a warning which should be reported as an error to make sure it is spotted.
Given that debug messages are already output as a light GREEN colour, then hopefully this request might not be too difficult to be implement?
Of course, I could be incorrect in my thinking.