It sure looks very red....ish....You've probably already guessed it. Yes, it's one more installation of Djurgårdsljus. This one is the street, Allmäna gränd, in front of the amusement park Gröna Lund. Half of the street lamps were covered in red, the other half in blue.
Allmäna gränd, Djurgården (map) 6 March 2010