The Web versions contain fewer symbols and dingbats, no enclosed alphanumerics, no Alternative Fractions, and no Petite Capitals. They do include the same colour glyphs as the Print versions, and they are hinted. Only a few software applications currently support coloured glyphs, so they will use a black fall-back glyph. Most modern web browsers do support colour font technology. 

http://www.softerviews.org/FontCreator.html#CreatingColourFonts

If publishing to a web site from WebPlus you can install the Web version to reduce the data that needs to be downloaded to view your web pages. Browsers will cache web fonts, so it is not a big issue, but first-time visitors to your site might notice that it loads a bit slower if you use the Print version. 