Their web site has moved, the new location is:
http://sattagis1.dza.fc.ul.pt/~cabral/projectos.html
(for me, I used AltaVista Babel Fish to translate from the site's Portuguese)
hexcolorpicker has been pretty buggy for me for some reason, this is flawless!
Only little thing I have to say is: why a "quit" button on the main UI? It would seem to make more sense to have the red top left close window button not grayed out...
Very useful, the best in the category if you need something simple (together with HexColorPicker). The complimentary colors are a handy feature. If it offered a way of saving sets it'd be nicer.
The basic HTML color picker could do with a few more extras - like, displaying some sample text.