Well I finally finished my Lego Halo Master-Chief. I thought I would be able to use a gold Lego visor on the helmet but it did not fit so I had to improvise and use a gold sticker instead.
 
 
 
I also built this marine (the idea for which I also got from Saber-Scorpion but not the gun). I even made this ODST. I just got a space-police body and put a silver helmet with a black visor on the minifigure body.