"But what is the status of color compatibility on the Web now? Who has the update on color consistency and compatibility as of 2004?."
well Charles Upsdell has stats on colour-depth trends
http://www.upsdell.com/BrowserNews/stat_trends.htm
8-bit (256 colours): ~2% of page accesses
16-bit (65 536 colours): ~30% of page accesses
24-bit and more (16 777 216 colours, and more): ~64% of page accesses
AOL 8-bit (256 colours): ~5% of page accesses, by users of an AOL browser with image compression enabled
cheers