Now with photos!
And so we go from the oldest color term in our language, to the youngest. A quick word of explanation: All the colors of the spectrum have of course always existed, and the human eye has always (near as we can tell) been able to see them. What I'm talking about are the WORDS we use to describe those colors, and how we separate the spectrum into different colors. After all, the spectrum is a constant shift from red to blue; we could just as easily call it red, yellow, and blue, or the current system in color wheels, red, red-orange, orange, orange-yellow, yellow, yellow-green, green, blue-green, blue, blue-violet, purple, and violet-red. Or we could break it down into a thousand different color names (magenta, turquoise, cerise, cyan...) or we could just call it 'rainbow'. How we divvy up the spectrum is a cultural thing that varies widely around the world. I'm dealing with western civ and the English language because, duh, that's the only system I know. If anyone else wants to weigh in on how THEIR cultures do this, please feel free. I'd love to know.
So. Orange. The word, in English, has only been around since 1300-1500 CE, depending on what source you look at. The name of the color - and apparently the concept of orange as it's own color needing it's own name came from oranges - the fruit, which were brought back to Europe during the Crusades. Before that, the orange part of the spectrum was described with various terms for yellow and red together, one of them being 'geoluhread', or gold-red in Old English.
Orange dyes, of course, existed all along. They were probably referred to as shades of red, yellow or brown, though.
As with red, the earliest orange colorant was most likely ochre and other iron oxides. (For more on that, go back to Red, if you haven't read it already.)
One of the most common orange vegetable dyes in Eurasia, for most of it's history, was saffron. (Yes, the same as the spice.) Originally native to SW Asia, it was cultivated widely around the Mediterranean. Saffron is a flower that grows from a bulb, similar to and related to the iris. The part that's used as a spice and a dye is the stigma, the thready reproductive organs inside the flower. Each flower has three stigmas. It takes up to seventy-five thousand flowers to produce one pound of saffron 'threads'. In Italy and Spain, in areas that traditionally grew saffron, there are harvest festivals that include saffron-picking races. Because of the work involved to produce a useful amount of saffron, it has always been expensive; even now with modern production methods it is the most expensive spice in the world. Saffron has been used as a dye back into antiquity, all over Asia and Europe. In India and Asia, it was often used as an offering to the gods, either as a dye for religious textiles, offerings, or even in buckets of dye, sloshed over the outside of the temple. In Europe it was used as a medicine, spice, and fabric dye for the rich. I was told (many years ago, while studying literature), that the Greeks used saffron as a medicine for PMS, and because of that, the saffron orange color was considered feminine, and was the Greek version of pink (I would not swear to the truth of that; I can't find any info to support it - but I WAS told that).
Onion skins can also be used to dye fabric (and easter eggs) orange. Most of the vegetable dyes discussed in the red section, especially madder and brazilwood, can also be used to make orange.
Henna, native to Africa, the Middle East, and Asia, was occasionally used as a dye as well as it's more common use as a cosmetic. It only dyes protein fibers, and must be used with an acid, even when dyeing hair or skin with it (traditionally lemon juice was used as the acid). Use goes back to the Bronze age, at least. It's said that when Cleopatra sailed on the Nile, the ship's sails were dipped in henna first; it's unclear whether it was for the scent (henna is also used as a perfume) or the color.
And this brings us to fluorescent colors, of which orange is one of the earliest and most used. They 'work' in a very interesting way. All fluorescent or 'neon' colors contain small amounts of sodium fluorescine or rhodamine. Those two chemicals absorb light in the ultraviolet part of the spectrum (which we do not normally see with the naked eye) and re-emit it in various portions of the visible spectrum. The added 'light' registers in the eye and brain as something extra, and our brain reads it as fluorescent.
In Western culture, orange hasn't been terribly popular until recently. The current popularity is considered nothing more than a result of color overload; we've gotten so used to all the other colors, we're turning to orange as something new. Or so the theory goes.