There are so many distinct characters that have yellow eyes! Some (often the villains) are reptilian yellow, while others use yellow green contacts to give them the look of cats or other predators. Whichever character you opt to create, the right pair of lenses will finish off the look perfectly!
In this franchise alone, there are lots of characters to choose from! Mystique, Jean Grey (as Phoenix), Toad, Nightcrawler, and Sabretooth all have varying shades and styles of yellow eyes.
In this animated film, Hades and his cronies feature fully yellow eyes with black, iris-less pupils. Lenses are a must to pull off this look!
Crowley from Good Omens
In reference to this demon's storied past (he was apparently the snake responsible for tempting Adam and Eve in the garden of Eden), his eyes remain golden and reptilian even when he takes his human form, though he often hides them with black-lensed glasses. A pair of yellow snake eye contacts would provide the perfect touch to this cosplay.
Darth Maul from Star Wars
What a look! With prosthetics, costuming, and some serious makeup, this is a cosplay that calls on all your skills. Without the right lenses, though, it would fall completely flat.
These characters from Japanese folklore are shape-shifting foxes who, in their human form, can be identified by their distinctive golden eyes. They appear in both Eastern and Western pop culture, like Neil Gaiman's Sandman comic series.
Original Costuming Ideas
Yellow eye contacts are perfect for signifying a character's supernatural origins, especially if they have ties to an animal (like werewolves) or the demonic. But since yellow eyes do occur naturally in many creatures, they also work well to indicate that a character, while not supernatural, simply isn't human. Here are a few broad categories where yellow lenses might come in handy!
This is an absolutely classic look for werewolves, and it can be seen in many films and stories: the yellow-eyed wolf-man is sure to grab attention, whether you're planning it for a Halloween costume, a convention, or for a performance of your own. But wolves are only one option. Why not opt instead for a were-lion, or were-tiger, where cat-eye lenses can provide a contrast to the usual wolf-ish look?
While we don't typically see traditional "were-creature" style characters with reptilian backgrounds, there are still plenty of looks that call for a snake-like appearance, and, short of a full set of scales, nothing indicates a reptilian background quite as quickly as those haunting, flat yellow eyes.
Another classic for yellow lenses, demonic characters with yellow eyes are also easy to find in pop culture. The series Supernatural even referred to one character as "The Yellow Eyed Demon" for a time, and unlike some epithets, they meant it literally! Often, the best lenses for these characters pair yellow with other colors, so look for red or black and yellow contacts. Want to kick things up a notch? Opt for scleral lenses!
Here's an opportunity for the more naturalistic yellow lenses to come into their own. Since yellow or gold are not usual colors for humans, but they're still within the realm of possibility, they're an ideal shade for creating humanoid alien looks. They immediately indicate something otherworldly about the wearer, but without going quite so overboard as to look impossible.
While many zombie stylists (now there's a job description!) opt for white or red lenses, why not shake things up with a sickly yellow? This works especially well for the viral zombie apocalypse style of undead, since yellow sclera in normal humans is an indicator of illness. You can even try mismatched lenses for a truly haunting zombie look!