Pick a color, see what it looks like just a bit lighter and darker, then quickly copy it to your clipboard.
Also, the error page is a treat:
Err, I think there’s been a misunderstanding. See, the website you’re trying to access runs on a computer and computers are inherently dumb creatures. The little guy tried to figure out what you meant by that request but ultimately failed. He says he’s sorry.
Check it out here, what do you think?