This is one where setting a good example is useless, because it isn't noticed. I send email in plain text, and people still insist on responding in HTML with settings like black-on-dark-gray. They don't realize that plain text is a choice made for good reasons.
Black-on-dark-gray is, simply, not readable by this human being (who is already wearing bifocal lenses). If it's your easiest way to read, set your computer display to that--then you can read my messages as is easiest for you, and I can still read yours.
In the meantime, if I seem to be ignoring you, it's because you have taken extra effort to make your messages opaque, and I'm tired of taking the effort to undo it.
Wikikarma: copyediting and expansion of [[Alt hierarchy]]