There are numerous colours that were well attested by the time of the Exodus, but a set of three become the centrepiece of the tabernacle. These are the “sacred colours” of Exodus: tekhelet, argaman and shani--translated as blue, purple and scarlet respectively. These three colours decorated all the cloth items in the tabernacle as well as the priest’s garments and were used to colour the cloths that covered the holy items when being moved. Each colour is also used individually in the items or rites of the tabernacle. However they’re not generic colours as we might think in a world of chemical dyes; each was produced from specific sources which gave distinct shades of each colour. For example, while madder red was used at the time, scripture is clear that shani is produced by an insect.
As mentioned, shani is actually referred to as towla shani or “worm scarlet”. There is no question it’s a bug dye (“worms” including larvae of insects), made from an insect known as kermes. The female kermes insect produces carmine (we get the words “carmine” and “crimson” from kermes, while “vermilion” comes from the latin name for worm--the kermes vermilio) and has been used as a dye since neolithic times. While it usually produces crimson, the dye bath can be altered to get scarlet as well (crimson being blue toned, while scarlet is orangey), though the scripture uses them as parallel synonyms (ie Isaiah). Shani can only be carmine red. I’ve seen one or two people deny this since “the colour of fire is orange, not red”. But those people are morons; don’t look directly at them.
It’s also important to note (for later) that kermes is the only colour of the three that isn’t a vat dye. It’s what we know as a “mordant dye” because it requires an auxiliary (the mordant) to bind it to the fibre.
Kermes (red ground) on silk--the coronation mantle of Roger II of Sicily
The scarlet yarn also features in later interpretations of the rite of the day of atonement. In a ritual probably based on Isaiah’s prophesy, a scarlet cord was to mark the goat for azazel and after splitting it, half would be tied to the temple door and observed. It was thought it would become white if YHWH had indeed cleansed and forgiven the people. This also harkens back to the cleansing rites using the two birds, one killed and one freed.
There is really only one purple of note in the ancient world, produced by molluscs and more commonly known as murex. As mentioned we have examples of murex dyeing as far back as 1800 bc--this is the source that is intended when the word purple is used. The Greeks even called Tyre “Phoenicia”, the land of purple, because of the production of murex. Lydia sold murex cloth, and at times its production was funded and controlled by royalty around the mediterranean (this continued until the end of the Byzantine empire). In Exodus this colour is called argaman.
So like shani, argaman isn’t just a generic purple, it’s an item dyed in murex. “Tyrian purple” is the most prized form of it, produced from overdying in two breeds of murex according to Pliny the elder. The colour is sometimes known as oxblood, as in the ancient world the most prized shade was that of “clotted blood”. It’s more akin to maroon than a bright purple we may think of.
murex dyed byzantine robe--murex is apparently difficult to photograph. It is also unusual in that it darkened with time rather than faded, and could eventually turn black through oxidation. Thus the colours aren’t the most accurate.
This dye, the colour of blood, is the colour of cloth YHWH commands should cover the bronze altar. It is the only thing that is covered in purple alone--even the ark is covered in blue. There are no other uses for argaman specifically.
Tekhelet has an interesting provenance, or lack thereof. It’s the only dye of the three whose source isn’t completely agreed upon. The colour is almost certainly indigo blue on the chemical level so we do know basically what colour it was. But there are debates between Jewish writers over whether the indigo is produced by the indigo plant or by murex, and over what shade of blue it was. Talmudic writings do claim this colour was produced by a "fish" (ie shell-fish) and that indigo was a cheaper copy of the real thing. If so, murex is the most likely dye as certain breeds can produce blue with exposure of the vat to UV. The only other known animal dyes all produce shades of red.
The argument for murex is also compelling because there have been murex dyed blue items found in Israel from the time of Bar-Kokhba. So we know they were using it at that time. It seems odd to use murex if indigo could be used, because indigo production is comparatively simpler. That said there appears to be a tradition that the colours had to be "locally sourced". If true this would explain why murex was used for blue.
Tekhelet-dyed cloths covered almost all the items of the tabernacle service when they were on the move, with the exception of the altar covered in argaman as mentioned. The bread of the presence and dishes are also covered with shani-dyed cloth, after being set on the table over a tekhelet cloth. All the loops and tying cords of the tabernacle were also blue. The priest also wore a tunic entirely dyed in blue.
Tekhelet is of particular focus for Orthodox Jews because it is the only colour laymen were commanded to wear on the tassels of their garments (the blue of the flag of modern Israel commemorates the blue tassels of the prayer shawl). For some time the colour has been considered “lost” because of the disagreement over the dye source--again not any shade of blue will do.
The blue version of murex on wool from around the time of the Bar-Kokhba revolt. These dyes were prized at least partly because of their unmatchable fastness.
Interestingly, the same three colours were also important ritual colours in many other cultures, as far away as the Americas (with different sources--see the traditional Oaxacan wrap skirt for a different configuration of them). This has to do with the beauty and general fastness of the colours as well as the difficulty of producing them; murex alone is historically one of the most expensive and labour intensive dyes to produce. When YHWH demands everything be made with gold we think that made it precious. But murex was equally precious (in the modern age, it’s actually MORE precious. Than fricking GOLD. Yeah). When scripture speaks of people of status and security, blue, scarlet and purple are mentioned. Across the world these colours symbolize wealth and status, or as YHWH himself says, “glory and beauty”. But they also are tied to other things. More on that in the next post.