Is this Northern Light or Purple Power?

I've bought Norther Light seeds. It's almost close to finish, but its turning all purple. Does the cold climate have something to do with the color? or might have I got a batch of purple power? tell me what you think this plant looks like. Northern light or mystery strain?

Looks like NL to me, and yes leaves turn purple when exposed to cold temps.

Maybe try Googling images of the two strains and see which matches up best. =)