Speaking of SEO...

I was on my way home the other day, which is one of the times that I always seem to get these random ideas... for some reason SEO came to mind. Personally, I don't care all that much about SEO (various reasons that are irrelevant for this), but I understand the purpose of SEO and keywording, and wondered about the method of implementation...

I've seen a number of sites where there is a tags/keyword section on the home page or even various pages within the site, which look like a dictionary listing. Personally, I've never cared for this and have always felt that it took away from the site (particularly one that is meant to be displaying images/artwork). So, what occurred to me is.... wouldn't it be just as effective (for the bots who do the SEO searching) to have the lettering in identical color as the BG, and blend in 100% with the site - as to be invisible to the casual observer? The bots (as I'd think) aren't looking for contrasting color between your BG and font color, so couldn't you place black text, on your black BG and have all the tags there for SEO, but not visible for clients to see?