I dont think the league would allow the gray as the dominant road color. I believe the leagues required the main the road jersey to be white, just like in baseball where home needs to be white, and road needs to be gray. So gray will remain alternate.
Home i dont think will ever change, or not for a while at least- is blue on blue
Road-
White top/Gray bottom- Ive said this before and nobody has given me a good answer yet. I dont get the white top and gray pants combo. Only gray in uni is on the logo on helmet. They ditched them this year so I was happy about that. In fact, they have never won in that combo. They went 0-3 against division foes in 2012.
Grey on grey- love it, but its alternate. Cant do anything about that
white on white- Im in minority, but i like this one. Its a clean look and looks great when dirty on mud fields like Washington and GB
White top/blue pants- My favorite Road combo. Ive watched SB so many damn times so the look is etched in my brain. I think its my favorite combo of all of them. I think they should stick with this one for most games.