Yellow, like red, is easily reproduced and so has a long history. Which means this will be a long post. As with red, I will put the names of specific colorants in bold, so that people can skim down and read the parts that are interesting to them.
The WORD yellow, in the English language, goes back to Old English versions of 'gold', which I assume referred to the metal as well as the color. The first known use of the specific word yellow is in Beowulf, written down sometime around 1000 CE.
The oldest yellow colorant was probably ochre, again, as with red and orange (and brown, but we haven't gotten there yet). It was probably natural to move on from there and grind up other yellow rocks and paint or dye with them. One of the most common, dating back as far as the Roman Empire, was orpiment (that's a picture of it in rock form, at the beginning of this paragraph). It's a mix of arsenic and sulfur, making it quite toxic. In Asia it was used to dye fabric (no info on deaths from wearing said fabric), and in EurAsia it was used as a paint, until the 1800s when other, safer ways to create yellow were discovered. It is still used to make fireworks look yellow.
Other yellow paints were made from cadmium, antimony, and lead, but have largely been phased out, also due to toxicity issues. Cadmium yellow is still used to color plastics, though. Titanium yellow is a newer colorant, and used as artists' paint, plastic colorant, and in ceramic glazes.
Indian Yellow is the big mystery, certainly of yellow in general and possibly one of the biggest mysteries in the history of painting. Starting in the 1400s CE, little nuggets of yellow... stuff... were shipped from India to Europe, where it was ground, mixed with binders and carriers, and used as a paint. It was also used as a paint in India (often to color the robes Krishna wore). Yet no one's really sure where it came from. In the 1880s, a letter appeared in England, describing the method used to make Indian Yellow; cows were fed mango leaves, then their urine collected and evaporated. Everyone was (supposedly) horrified by the animal cruelty, laws were (supposedly) passed, and the color was made (supposedly) illegal. Yet when Victoria Finlay investigated this tale for her book ("Color"), she couldn't find a trace of it. Other than the original letter, there's no paper trail. No laws on the books in England or India, no mention of any of it in newspapers, nothing (she looked in large archives in both countries, it was a respectable search). When she visited the village named in the original letter, where the color was made, no one knew what she was talking about. On the other hand, several people have tried to replicate Indian Yellow (by feeding cows on mango leaves, etc), and have a hard time believing it could be mass produced. So. Nobody knows. (I like knowing that in this modern world, we still don't know everything.)
Weld was THE yellow dye in Europe until it was replaced by synthetic yellows in the late 1800s. Native to the Middle East, it was used there from 1000 BCE and possibly earlier, and was naturalized in Europe. Weld, with madder and indigo/woad, made up the three primary colors, from which most other colors could be created, giving dyers a near-rainbow. (Because of the yellowish shade of madder, it did not create an attractive purple when mixed with indigo, but that's another article.)
Safflower is the other major yellow dye of the ancient world. It was used at least as far back as Twelfth Dynasty Egypt (1800s BCE), and was found in Tutankhamon's tomb. The flower heads are used, and can produce yellow and pink dye, depending on how it is processed. Basically, the yellow dye has to be removed from the flowers, then they yield pink. It's non-toxic (this plant is also where safflower oil comes from), doesn't need a mordant, and is reasonably colorfast. If you wanna play with natural dyes, this is a good one to start with.
And this brings us to tartrazine, or FD&C Yellow 5, as it is known here in the States. It is a coal tar derivative and is considered safe as a food coloring (think about that for a minute). The chemical makeup is similar to aspirin, and has been known to trigger allergic reactions in many people, to the point that some European nations have made it illegal. It is also implicated in 'hyperactivity' in children, one of the few chemicals to have legit clinical evidence to back up the claim (sugar, on the other hand, has never been shown to cause anything but tooth decay). Here in the US, it is required that foods containing Yellow 5 be labeled as such, so people can avoid it. Of course that's easier said than done.
On a personal level, my experiences with yellow have also been odd. Navy SEALs tell me that sharks are most attracted to the color yellow and I should never, ever buy a yellow bathing suit. They actually call it 'yummy yellow' because that's apparently what the sharks say when they see it - yum. And when I used to work at the local newspaper as a kid, yellow paper was known to trigger all kinds of allergic-type reactions with the ladies in the mail room; skin rach, itchiness, and sneezing were most common. No idea what colorant was used on the yellow paper, but it's darn interesting.
The compliment of yellow (the color wheel 'opposite') is purple. Yellow is often associated in the West with bad health and/or aging. But in China, only the emperor was allowed to wear yellow. Cultural symbolism for yellow is probably the most erratic and widely varied, of all the colors. Oh. And people of European heritage, with white skin, almost never look good in yellow. People with darker skin, though, with a brown tone, look magnificent when wearing yellow.