Adding style to each category

I want to give every category (for example: Politics) a different style.

So I tried something like this within The Loop:

<div id="style-<?php the_category(); ?>">
blablabla all kind of posts within Politics
</div>

So I can implement in CSS:

div#style-Politics {
color: blue;
}

But for some reason this does not work, the problem is the php statement.

How can I achieve what I want?