If a computer is used mainly for word processing or spreadsheets, high colour depths and sound capabilities are not very important. Emotive aspects of colour. Apart from the more obvious 'attention seeking', or 'traffic lights colour-coding' uses of colour, its ability to stimulate emotions is of paramount importance. Colour can create moods and send subliminal messages to reinforce your communication - if used properly. In the wrong hands, it can just as easily turn people right off.
Colours change with their surroundings.
The perception of a colour changes depending on what other colours are next to it. Put a bright magenta against a purple and you get a contrast, but it is fairly static. Put a bright magenta against a vermilion red and you get an effect called scintillation that causes the colours to vibrate against one another. Quality not quantity. So, the web-safe palette still has its uses in the year 2000.