Black was the hardest colour to dye and that is why it meant something

Making black was a genuine problem

Most natural dyes give a colour by attaching to fibre and reflecting a particular part of the spectrum. Black requires absorbing nearly all of it evenly, and doing so with materials that individually produce browns, blues and greys means building the colour up in layers.

The traditional European method was to dye first with woad or indigo to lay down a dark blue base, then overdye with other materials, frequently involving iron salts, to darken it towards black. Each stage cost time, material and skilled judgement, and the result was expensive.

It was also unstable. Iron-based blacks degrade the fibre they are applied to over time, which is why surviving historical black silks are often shattered and split while other colours from the same period are intact. The colour was literally eating the cloth.

Expense made it a colour of status

Because a good black was costly, wearing it well signalled wealth, and in several periods of European history a rich black was the most prestigious thing a person could wear rather than a sober alternative to colour. It carried authority in courts, and it was associated with dignity and seriousness rather than with restraint.

The cloth mattered as much as the dye. Black on a fine wool or a lustrous silk shows depth and reflects light; black on a coarse or cheap cloth reads as flat and grey. That distinction was visible to anybody at the time, and it’s part of why the colour could signal so precisely.

Sumptuary regulations in various places attempted to restrict who could wear which materials and colours, and while their enforcement was patchy and their aims were as much fiscal as moral, they are evidence that colour was understood as a marker to be controlled.

Mourning turned it into an industry

Formalised mourning dress, which reached an elaborate peak in nineteenth-century Europe, prescribed black in specific fabrics for prescribed periods, with a gradual transition through greys and mauves at the end. That created a large and reliable market for black cloth, black crape, and everything else the code demanded.

The requirement was heaviest on women, and the expense of complying was considerable. Businesses grew up to supply it, and the codes were detailed enough that a person could read a great deal about a family from what its members were wearing.

When the elaborate version faded, black retained the association with mourning in many Western contexts while also carrying every other meaning it had accumulated. It is worth noting that the colour of mourning isn’t universal, and white and other colours serve that function in a number of cultures.

Cheap black changed the meaning again

Synthetic dyes and, later, dyes developed for specific fibres made a fast, even, inexpensive black available to everybody. Once the colour cost no more than any other, it could no longer signal what it once had, and it took on the meanings it holds now.

Those meanings are various and partly contradictory: formal evening dress, professional uniform, a certain kind of urban wardrobe, subcultural affiliation, and the practical fact that black hides marks and goes with a great deal else. A colour that is available to all becomes a canvas for whatever a group wants it to mean.

The practical wardrobe argument is real, though it’s often overstated. Black is the least forgiving colour for showing lint, dust and fading, and getting several black garments to match each other is famously difficult, since they fade in different directions.

Why black garments still misbehave

Deep shades need a great deal of dye, which means more of it sits on or near the fibre surface than in a pale cloth, and surface dye is what rubs off and washes out. That is why black garments crock onto lighter ones and why they lose depth with washing faster than mid-tones do.

Ultraviolet light attacks the large amount of dye present, and the result is not a paler black so much as a shift towards a rusty brown or a grey, depending on the dye chemistry and the fibre. Different fibres in the same garment take black differently and fade differently, which is why the stitching sometimes ends up a different colour from the cloth.

Washing cold, inside out, without excess detergent and away from direct sun slows all of it. It does not stop it, and a black garment that is worn and washed often will eventually announce that it has been. In that one respect the colour has not changed at all since it was expensive.