Am I right in thinking that the page of topcolors is a list of the topcolors that some account is currently using?

(I just set my topcolor to b000b5 because I am incredibly easily amused.)

You need to reach a certain threshold before you can use Top Colors. I think it maybe 500 karma points, but don't take my word for that.

When you do get the feature, you can go to settings and enter a hexadecimal entry for topcolor. The banner on every page of HN (except in Add Comment) will then change from the default orange to the color you specified.

The threshold is indeed a bit lower than that; I have topcolor with 296 karma.

Ok, thanks for pointing this out. It may be a 250 karma threshold, although we can't know for sure as it is always changing (due to inflation from new users): http://www.jacquesmattheij.com/The+Unofficial+HN+FAQ#cantdow...