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Thanks.
Web smart colors are those which can be represented with a 3-digit version of the fiull hex code in your css files -- that is, the digits double up, #1199bb and so on, so you can write #19b as a shorthand.
There is some sense in this - if you ever get to see your pages on a 256 color set up you'll know why.
Still, I agree that there's not a lot of problem today. More important for me is cheking in both 16-bit and 24-bit color depth. Depending on what you've created you may see a surpise or two - especially if you assume that a hex color will naturally match, say, a gif color. I often provide a single color gif for a tiled background in addition to a background-color, just for this kind of contingency.