Links that you’ve visited recently in your browser are black, unvisited links are blue – that likely accounts for the difference.
I added Simple Links since it was the most updated. However, how do I make the links appear under the “LINKS” label on the static page?
The default Links area in the sidebar in Coraline is designed to work with the old Links feature that used to be part of WordPress core. When the feature was removed from the basic WordPress install, it was moved into the plugin I referenced earlier, so people could still use it.
If you prefer to use Simple Links instead, check your Widgets area and see if the plugin gives you a widget you can drag into the Primary Sidebar area, under Appearance > Widgets. That widget will be displayed instead of the three default sections that Coraline comes with (Search box, Recent Entries & Links). You can add back as many other widgets as you like in addition to your new links.