Wiring for the case to f-panel

Hi, I am trying to build a new one, got all the basics, although my case front panel that wires to the f-panel on the mobo is not altogether specific as to the + Plus and - negative wire configurations, it does have two power LED wires that are marked + and - , all the rest of the plug ins are anyones guess, the speaker plug has two pin connector, one black, one yellow wire, the HDD activity plug in has 2 pin, white wire, blue wire,
pwr supply has 2 pin , white wire , yellow wire, from all this I am pressuming that white wire is the common negative, would this pressumtion be correct??
Also my mobo does have a 3 pin power LED plug in, my case only has 2 seperate plugins marked plus and minus for power LED, where can these go or can they even be used?? My Mobo is Gigabyte GA-MA790X-UD4P , dont want to cross up any connections, Any help appreciated!
Thanx

Great!! I was just wanting to make Absolutely sure. I appreciate your answer.
Thank you!!