In this Illustration, I focused on creating a color pop at the focal point. 
Orange and blue are complement colors so implementing a lot of warm oranges on the lit up side of the buildings against contrasting purple and blue shadows helps make the illustration even more interesting. Having that color pop contrast take place right at the focal point helps draw the eye right to it.
the Pied Piper
Published:

the Pied Piper

Published:

Creative Fields