As I mentioned, in 301, we have the blue lights. In 304, we get our last real glimpse of Brian's bedroom until 309, and the blue lights are still there.
We first see the orange in 306 at Woody's, where Justin is licking his wounds. I guess you could say that orange represents him at this point. Also, in the eye fuck scene in 307, we get a hint of the merging of blue and orange. And finally, in 309, the lights in Brian's bedroom have changed from blue to orange.