The Pink City i.e. Jaipur in order to maintain its colour status drives people to paint their houses and the walls in the same colour
The walls have a simple red paint with a white boundary, see above. This gives a nice look throughout the city. A similar thing runs in Bhubaneshwar with tribal drawings on the walls.
One, it stops people from spitting, two, it stops politicians and others from defacing the walls.
Our cities need more such practical solutions to make the area more comfortable. With the mess around in a city like Mumbai, it is but so easy for some to put some stray objects around (with no one the wiser).