No, no, no, in Florence, they can be red numbers or black numbers too!
I recently posted a long digression on Florence’s address system but if you are like me, you need additional study guides for remembering all this information. Here’s a great commentary on Florence’s idiosyncratic address system. The source follows at the end.
During the RISORGIMENTO, or “resurgence,” the political and social process that unified Italy during the nineteenth century, the city of Florence experienced massive urban renewal. It had become apparent that businesses that were once simply people selling from carts, market stalls, or out of ground floors of family homes were now evolving into the kinds of operations we know today— large and small shops separate from street and home. This posed a distinct municipal problem: how to distinguish business addresses from home addresses. Since it would have been impossible to renumber the entire city, a unique numbering classification was born. As a result, to the dismay and confusion of today’s visitors, buildings in Florence operate on two numbering systems. Buildings housing commercial businesses have red numbers, meaning that the number listed in the address is followed by an r for rosso. The red number on the facade of the building tends to be engraved into a square marble slab, and, with age, appears to be anything but red. Residential numbers are indicated in black, even though the numbers on the buildings are actually blue, on a white ceramic plate.
While the addresses in this guide are shops and hence should be red, this is not always the case. The red and black numbers do not necessarily correspond (i.e., number 57r can be directly across the street from, say, 100r, and next to a black 31). Moreover, examples of “red” numbers styled in black (see below), and vice-versa, are apt to crop up every now and then. When all else fails, consult the map at the beginning of each walk. Should you become completely frustrated, a stop at a gelateria or wine bar (also indicated on the map) is a highly
Fili, Louise; Apatoff, Lise (2015-03-17). The Cognoscenti’s Guide to Florence: Shop and Eat like a Florentine (Kindle Locations 106-110). Princeton Architectural Press. Kindle Edition.
And for people who like their information via video, I give you this!