As linked and referred to earlier, Randy Brown of Open Artifact has already come up with a Purple Number Plugin for WP. You can see the implementation on his own blog. In simple terms, it allows hotlinking to a specific paragraph in a WordPress article.
Here is the link to the hack.
That implementation is really annoying to me. The purple color distracts my reading. I think if you’re going to implement hotlinking in each paragraph you have to be really careful with your design and choice of colors.
They are called Purple Numbers for a reason. 😉 But, never fear… CSS is here. Just simply change the color inside the plugin.
Hope this helps.
I’ve updated PurpleNumbers to v1.0. You can find it and details here.