First, choose a colour for each part of your city;
Second, paint all the city appliances and structures with the corresponding colour;
Third, when you start moving in any direction, you add some blending to the original colour. So, when you’re walking in any direction towards other parts of the city, the colour will react to your movement and it will start to blend with the colour previously selected for that region.
It’s then possible to change Torino coloration according to a collective conception. Inventive at least!