The fact that different brown shades are very common when it comes to leather shoes, and leather products in general, is due to simple practical reasons historically. This article explains the whole thing closer.
Tan, dark brown, chestnut, nougat brown, tobacco, mahogany, maroon, espresso, and so on. In addition to black, different brown shades are by far the most common when it comes to classic leather shoes, and as mentioned, the same applies to leather products in general. Today, it is something that we are used to, something that feels natural to us, we think it looks good. The reason for this is that brown shades for centuries have been the most common color of leather, and the reason is that brown leather is simply the easiest to make. It’s natural.
Tanned leather has been made since early stone age, about 8,000 years BC. Probably by chance, it was discovered that there are tannins, tanning substances, in tree materials like bark and leaves. Historians believe that the untreated animal skin that was used as clothing at that time was laid in puddles of water to soften, and there were plant parts like bark and leaves in the pools that made the skin more resistant and when the people put the puzzle pieces together they had discovered tanning of leather. A method that has since been developed in many different stages, but only made with natural ingredients until the mid 1800s, when the English chemist William Henry Perkin invented the first synthetic method of coloring leather and fabric called aniline dyeing (very toxic, and the synthetic dyeing that is being made today is still called aniline dyeing but it’s made with completely harmless synthetic substances, aniline stopped being used a long time ago).
If you tanned leather with bark, which as you know is brown, then the leather for obvious reasons became brown. Depending on the bark and plant substances used, the shade varies, but non-dyed vegetable tanned leather is more or less always brown. People early in history wanted to express themselves through their clothing, so they started working on coloring the leather with different natural substances early in history, both from plants, berries, insects and other dyes that were used. It worked excellent on fabric fibers that easily absorbed the dyes and kept its colour relatively well, but leather was often more complicated, and although it was possible to solve other shades early, it was more difficult, and the result and colour durability varied. Therefore, brown shades have been very common throughout the centuries.
During the early modern era after year 1500, a new effective method was discovered using logwood to dye black, it quickly became popular and made black regarded as a formal color, which remains true still today, especially when it comes to shoes.
At the same time as synthetic tannins became common in the mid 1800s, the chrome tanning were also invented, and chrome tanned hides become as you might know blue grey in colour. By that time, brown shades for leather, along with the common black, had been such a strong part of how we perceived leather products, that it simply has lived with us since then. And while other shades like blue, green and purple have become relatively popular in recent years, it’s likely to take a long time before shoes in brown shades lose their huge popularity.