I've installed network-manager-gnome as the main WI-FI program, but you could
also choose wicd-gtk to manage connections in the panel.
You can tweak the colors in the Panel Preferences (The panel preferences can
be opened by going to Settings → Panel in your applications menu. You can
also access panel preferences by right clicking on your panel and going to
Panel Settings. If you right click on space occupied by a panel plugin, you
can access panel preferences by going to Panel → Panel Preferences....)
But I also suggest this package you can install: gtk-theme-config
It can change the highlight colors of the theme, the panel and menu colors,
as in this screen shot.
