Are there any studies that show what colors and fonts that are best for reading in a website?

Tons of them in any basic html lession you read off the web or from a book. Colors are a whole science to interactivity and fonts are limited in html but not graphics. Still combinations of fonts and not over combining does play a key.

I've been starting to see forums that allow you to use a custom skin.

I haven't changed any skins on forums personally, but do you think that offering that option is better than researching to provide one effective design with no user options?

Personally, I don't think it's a good idea. Part of developing an online community and making it successful is building "brand awareness" for lack of a better term. It's best if you control it completely.

The only way to make skinning work, I think, is if you completely control the skins, and make sure that they all fit within the design aesthetic of the site.

Pete

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Reverend Pete
Code Of Paint
Learn to program using Flash

I was work all day on trying to manipulate a skin and I finally gave up. To bad I really like the template.