Wow, this is stunning! I love the looseness of your brushwork, and i really think you've captured a cold mood with the de-saturated colours. Reminds me a little of San Fran the last time I was there . Just starting out with gouache myself, hope I can get this good someday ^.^ I was wondering, do you usually do a lose sketch before going into gouache? Or do you just paint it?
Oh it's a lamp? I thought it was falling snow up close.
Lucky with gouache there's a couple of easy fixes you could do.
You could hit up the white with some of the yellow shades you have on the buildings and bus. I personally think this would pull the whole picture together even more since you have the yellow synonymous through the painting except on that side. It would also give a nice "U" shape to lead your eye through this amazing scene you have going on.
Or you could take a damp brush and lift up some of the white till it's not as intense.