I'm calling it right now. Ep7 Luke is going to be a what we know as a Gray Jedi.
Reasons why will be in spoilers
>Most if not all have seen the picture of Luke in a very light colored, possibly gray, with white. He also has a gray cloak
>We see Jedi all the time in brownish robes, ranging from light brown (tan-ish) to dark brown
>All Sith/Dark Jedi wear Black
>We see Anakin move from tan (end of Ep1) to tan with darker Brown and Black (Ep2) to extremely dark Brown (almost black) with Black(Ep3), and finally calumniating with his iconic black suit
>We've never seen Jedi wear any robes like this and I think that's a very symbolic thing
>I could be entirely wrong since white/gray would be the complete opposite of the black from what we've seen so far, maybe indicating that Luke has gone extremely far into the lightside, side of the spectrum