Well, using and editor and a keyboard would be one way to do such a thing.
s/#ccffcc/#000000/ can be used in a variety of editors, and with Perl too.

If you're on a *nix system and want to replace all occurences in a file, you could use

perl -i -pe's/#ccffcc/#000000/' file.html
[download]

On DOS-based systems you probably need to use double instead of single quotes.

Good luck!