Separates active network plugins from inactive ones on the WordPress network plugins page. Requires WordPress Multisite.
The plugin was originally inspired by WordPress MU, which used a blue color to identify which plugins were activated network-wide. Also, in MU, network plugins were also neatly separated from regular site plugins.
When WordPress 3.0 came about, all plugins were merged together into the regular plugin list. This made things hard to administrate and hence the genesis of this plugin!
So to answer the question, the blue color is a throwback and tip of the hat to the ol' WPMU days.
The original plugin description is below:
WordPress 3.0 is cool like Thelonius Monk, but for super administrators coming from WordPress MU, if you head on over to the plugins page, you'll notice something missing. Network (or sitewide) plugins are now merged into the entire plugins list! If you're like me and missed how your network plugins were listed at the very top with the uber-cool blue color, then you'll love this plugin!
Good question! I initially wrote this plugin for WP 3.0 when it was hard to distinguish between a regular plugin and a network plugin.
WP 3.1+ now offers two screens to administrate plugins - one for regular site admin use and another for your network. It's a little better now, but this plugin is still useful from a usability perspective. Give it a shot and you'll see! :)