Curious Florence: Red or black numbers?

It may happen that looking for the address of a shop becomes confusing for those coming from outside Florence, because in the Tuscan capital a differentiation is made between the house numbers, written in black, and those of commercial activities, marked with red numbers.

The origins
The civic numbering in Florence was introduced in the eighteenth century, when the houses were indicated by the name of the owner family or according to "parish numbering" established on the basis of the Status Animarum (Stati delle Anime), that is, registers compiled by parish priests with the personal and religious data of all parishioners.
When Florence became the capital of the United Kingdom of Italy in 1865, things changed, starting the numbering on the side of the road closest to the river, while for the streets parallel to the Arno, you followed the course of the river starting from the part upstream.
The introduction of red numbers to distinguish houses from non-residential entrances was actualized in 1938.

The problem 

Unfortunately, this distinction creates many problems, especially for geolocation on digital maps, where the red numbers are not registered. The difficulty in geolocation depends in particular on the technology used by the Google Car, which, as it passes through the city streets, automatically reads the names and house numbers. When it finds two identical numbers, even if they are of different colors, the system does not recognize them and records only one.
Anyway, the presence of red numbers is destined to decrease, given that whenever possible, they are eliminated or replaced by the toponymy office.

If it is true that this system creates a lot of confusion, it is also true that it is a peculiarity of Florence (the only other Italian cities to adopt black and red numbers are Genoa and Savona), so we will certainly be very sad when the red numbers disappear for good!