As the others have indicated to BOTH of your postings, the feature
was added in Excel 2002. Please post only once and wait for your answers
to roll in, which they actually did before you posted the second time. Half an
hour is very short time to have waited for someone else to be answering your
question. A day or two would be more appropriated and work on something else.
However, I can hardly see moving up to Excel 2002 for something minor
like worksheet tab color, which really isn't going to gain you much of anything.
There are better things that you can do with the worksheet tabs such as
sort the worksheet tabs see SortALLsheets macro in
http://www.mvps.org/dmcritchie/excel/buildtoc.htm#sortallsheets
and comment about color sheet tabs in
http://www.mvps.org/dmcritchie/excel/colors.htm#tabs
You can rename some of your worksheetnames so that sorting will keep
groups of sheets together. i.e. k.FunctKeys, k.ShortCutKeys -