Blue! Overwhelming blue! Red is also magnificent as well as blue!
I'm going to go right now! Look forward to blue!!
I guess he really likes blue... Well of course, I'm going to guess that blue = Kanna and red = the alien girl. "Blue Rain"'s also probably a pun on "bluray" (compare ブルーレイン to ブルーレイ) since this is a more detailed version of a scene from last episode and it has widescreen borders.
