I'm squarely in the "black and white snob" camp, although I'm not exactly *against* color...
Here, let's take a look at what happens when I do black and white:
http://umlauthouse.comicgenesis.com/d/20051213.html
You can see what's going on, you get artwork, you get story. Efficient. Clean. Let's not beat around the bush here, Color still has a cost on the web: TIME. To do correctly, color takes more than three times as long as black and white, because now in addition to lighting and grey choices, you have to think about what colors are going to *mean* in your comic. If you don't, you WILL end up with monstrosities like the following:
http://umlauthouse.comicgenesis.com/d/20050218.html
And keep in mind I was actually doing a little thinking about this one. If you mute your colors you'll probably do better, because a strong color is going to evoke a strong response, and just having lots of strong colors can really distract.
Generally, I find color comics fit into the category of "creator is an artist, not a writer" comics which generally I give up on because no amount of phong shading will get me to read a comic with a weak story. Generally, the people who do black and white are more likely to rest in that "sweet spot" between Writer and Artist, when both artwork and writing are worth getting. Really, really bad artwork CAN kill a story, but I find it takes a lot more suck in the artwork to make me lose interest than in the story...
Lately, I've been doing "partial color" on my comics. Nearly all of it is greyscale, but when I'm portraying a few extremely specific things I use color. The color adds emphasis, but is also having a cumulative story impact in that as more colors are added to the reader's vocabulary, later I'll be able to tell parts of the story in a subtext made out of the colors.
Early on, I have to be fairly blatant; the nanotechnology in the vial is stated as such. This is the first time the reader sees the teal color which will later be associated with ALL nanotechnology, so I have to say it out loud.
http://umlauthouse.comicgenesis.com/d/20060120.html
When we see it again, we've already heard it said that it can "build a fortress", and if there was any doubt, there's the color again:
http://umlauthouse.comicgenesis.com/d/20060127.html
With repeated exposure, along with explicit references to each new technology accompanying color, I'll ultimately end up with a symbolic language that will be able to stand alone without any dialog to back it up.
I HOPE.