Hmmm...

If you look at the updated article, it makes a bit more sense...

"8. Non-standard link colors. Continues to be a problem since users rely on the link colors to understand what parts of the site they have visited. I often see users bounce repeatedly among a small set of pages, not knowing that they are going back to the same page again and again. (Also, because non-standard link colors are unpleasantly frequent, users are now getting confused by any underlining of text that is not a link.) Severe "

Definitely, do NOT underline text that isn't a link!!! Even I get annoyed and confused by that. But non-standard link colours are ok, as long as it changes when clicked on. Having different colours contributes to the individuality of the web - and as much as I love purple, it doesn't go with EVERYTHING!