Gray and black brick architecture,
Pink Floyd’s song “Another Brick in the Wall” criticizes the alienating and depressing educational system, where people, or children, are portrayed as bricks because of their homogeneity,
Whether in the way of living or thinking in a society that does not like opposition very much.
Brick works very well in this comparison, as it has changed very little throughout history and around the world in its rectangular shapes.
But this does not apply to their colours. Although we tend to think of red when we talk about bricks, there are endless possibilities for shades, depending on the composition of the pieces and their manufacturing process.
The term brick refers to a block composed of dried clay, but is now also used informally to refer to other chemically treated rectangular building blocks.
The clay brick composition, which is the most traditional, as Tahsina Alam points out in her article for the Civil Engineering website, contains the following components:
Silica (SiO2) 55%
Alumina (Al2O3) 30%
Iron oxide (Fe2O3) 8%
Magnesia (MgO) 5%
Lime (CaO) 1%
Organic matter 1%
Clay is a hydrated aluminum silicate containing alumina and silica. The color of the bricks is affected by the chemical and mineral content of the raw materials, the temperature and the type of kilns used.
This is why it is common for there to be slight variations between solid brick lots, which often appeal to designers aesthetically.
The more iron oxide in the formula, the redder the finished piece will be, and the more lime, the whiter it will be.
As discussed in this article, “Iron oxide gives bricks a red color when burned when there is an excess of oxygen, and dark brown or even black when there is insufficient oxygen.

Black brick
Black brick is attractive because of its sober and simple aesthetic. In London, solid brick buildings are very common, and were mainly built during the 19th century.
Because of the soot in the highly polluted London air of the time, the bricks ended up looking gray or even black.
As conditions improved after 1956, the cleaned buildings returned to their original color.
But there is also a way to add pigments to the mix to make the bricks naturally black.

Gray brick
As for gray bricks, they are generally blocks that do not use clay in their installation. There are three main types: concrete bricks, sandy lime, and fly ash.
In the case of concrete blocks, they can take on several different shapes, with a distinct color due to the cement present in the mixture.
In sand-lime bricks, a mixture of lime, sand and water is compressed and hardened in kilns under steam pressure.
In this case, the blocks turn light grey. Fly ash bricks are made of by-products of coal burning and other industries, and are mainly composed of fly ash and cement.
They weigh less than concrete and clay bricks, and because of their low absorption rates, they tolerate heat well, and their color and uniformity are very visually pleasing.