Living in London my palette may be greyer than yours.
Does yours have a blue sky? Colourful buildings?
I am using such a palette at the moment and so far it's pretty grey.
But looking at my photos of skylines and urban scenes:


A poster of the London skyline:

and some palettes called "Urban skyline":

Color by COLOURlovers

Color by COLOURlovers

Color by COLOURlovers
I think I need to add more colour and make my skyline one I want to see