You might think that the only yellow beads you could find are made of glass. And you would be partially correct, since you’re probably thinking of a bright yellow color like the one below.
Most ancient beads of that color are glass, since the only other way to get a bead of that color was possibly painting wooden beads or glazing a clay bead. But that’s not the only shade of yellow we see in archaeological beads. Based on the methods I’ve discussed for determining primary and secondary colors of beads, the one below is also yellow.
I will say that the transition of these photos to web-based material is dulling the yellows of some of these, but they are primarily yellow. Some are a very light yellow, but they are still yellow. Some are orangey-yellow or greenish-yellow, but they’re still yellow.
It’s also good to remember that brown is really a dark yellow or dark orange.
Amber beads tend to be more orange than yellow (or more red) due to exposure to the air. Generally speaking, yellow beads are glass, stone, or ceramic.
This bead is also yellow:
Gold foil beads are more yellow rather than golden now, since the gold often degrades over time. But gold is a yellow color, so any gold or gold-colored beads fall into this category.
Yellow in glass is generally made by adding lead and antimony to glass. Tin also helps to opacify glass, and I’ve heard it connected to a yellow color (but I’m not certain on that). Yellow stone beads might be some types of agate, though I’m unfamiliar with many yellow stones being turned into beads in ancient times.