Some of the variants of the little orange XML button use more subdued colors. For example, I've seen blue "RSS" buttons. That raises the question, is the orange button too loud? Does it yell, "I am the most important part of this webpage"? Does it detract from site design?

Nah, I don't think so. I like the fact that it's orange and loud. Any other color would probably be too hard to find quickly in the clutter of many webpages...with the possible exception of red, but that would be too loud! ;-) If it were a big orange XML button, that would be too loud too. I'm sure there are sites whose designed is hurt by the orange button, but I suspect that they are the exception and not the rule.

If you want people to use your RSSAtomInfoBiteRDF feed (can we come up with a word for all of them? I'll post some musings about that later), then a little button that jumps out when you're looking for it is a good idea.