Fennel's Stupid Guide to Cat Genetics!

Eye colors

Eye colors are a bit different, because they aren't inherited, unlike human eyes. A cat's eye color is determined by how much melanin is in their eyes, and according to Messybeast, eye color and pelt color usually have little to no correlation with each other. However, like always, there are exceptions to this rule.

So, here are all of the possible eye colors that I know of!

Common eye colors:
-Green
-Amber
-Yellow
-Hazel (Greenish-brown eyes)

Rare/Breed specific eye colors:
-Blue (Regular or ice blue)
-Orange
-Copper
-Lilac
-Pink
-Ojos Azules (Messybeast described this color as "cornflower blue", I will explain this in the Mutations chapter)
-Turquoise
-Aqua
-Silver (Looks like pale gray)

Impossible eye colors:
-Purple
-Red
-Black
-White
-Brown (Copper is the closest you can get to brown)
-Dark/regular gray
-Anything else that seems ridiculous to you

Ok, so a bit of explanation for each of these!

So, the most common eye colors are green, yellow, hazel, and amber. Warrior Cats lied to you, blue is NOT a common eye color for cats. For some reason in Warriors, so many cats have blue eyes, yet there are rarely any cats with yellow or hazel eyes! I'm not expecting Warrior Cats to be genetically accurate, but I'd assume that a series centered around cats would at least know how rare blue eyes are in cats.

Copper, orange, turquoise, and aqua are all incredibly rare eye colors for feral cats to have. These colors are usually only found in purebred cats, since most purebreds are specifically bred to have bright colored eyes through artificial selection. Copper and orange have high amounts of melanin, while aqua and turquoise have lower amounts. Aqua and turquoise are usually caused in cats with specific coat patterns (I will get into that later) but copper and orange can be found in any colored cat.

Blue eyes are also quite rare, and ice blue eyes are a bit more than that. Blue eyes are usually only found in cats that have more than 50% white on their body, or have a considerable amount of white on their faces. Blue eyes are caused by a lack of melanin entering a cat's iris, so naturally, cats with less melanin in their pelts are more likely to have blue eyes. Blue eyes can be found in cats without white, but it is EXTREMELY rare.

So yes, all those blue-eyed cats in Warriors ARE in fact, possible. They just happen to be incredibly unlikely. About as unlikely as feral cats living in Clans, following an organized religion, and summoning their dead ancestors to help them fight off ghosts from cat hell who are rotting away in a stinky forest.

Silver eyes appear pale gray, and I don't exactly understand how they're caused, but silver eyes are a thing. I think it has something to do with extremely low amounts of melanin in a cat's eyes, but I'm not sure.

And finally, pale blue, lilac, and pink eyes can all be found in albino cats. As I mentioned before, blue eyes are caused when a cat has a lack of melanin in their irises. Albino cats usually have pale blue eyes, but due to the way the blood vessels in a cat's eye reflect, an albino cat could end up having lilac, or pink eyes, but both are less common than blue ones.

Heterochromia:

Heterochromia is a condition that occurs in many different species, not just cats. Heterochromia is when a cat has two eyes that are different colors from each other. This is INCREDIBLY rare, so use it sparingly.

When a cat has heterochromia, melanin only travels to one eye instead of both, leaving the other eye with no melanin. This is why cats with heterochromia always have one blue eye, since blue eyes have no melanin in them. And since cats with heterochromia have one blue eye, the majority of them are also either 50% white, or have a lot of white on their face.

Dichromatic eyes:

So, a lot of people like to complain that heterochromia is overused in Warriors OC's, and to be fair, it is. It is a ridiculous complaint to make about someone's OC, but it's still true that heterochromia is overused. If you want to make your OC's eyes cool but want to try something different, try dichromatic eyes!

Dichromatic eyes are also incredibly rare, and happens when a cat has two or more colors in their iris (kind of like a gradient). This is caused by different levels of melanin being found in different sections of the iris. This is the rarest eye color of them all, and it looks really cool!

Dichroic eyes can either have the outside of their pupil be one color, which fades into another, or the eye can be split into two or more sections with different colors that fade into each other. Any two or more possible colors can be found in a dichroic eye, and a cat with this condition would usually have two dichroic eyes.

Here are two examples:

Kitten Eye Color:

Kittens are ALWAYS born with blue eyes. When a cat is between 1 and 2 months old, their eyes will slowly fade into their adult eye color. Because of this, it's impossible to know a cat's eye color from birth. Not just because of what I just stated, but also because kittens don't open their eyes the day after they were born.

Aggressively stares at Bluestar's Prophecy

Anyway, that's all I have for eye color! Remember, don't be Bluestar's Prophecy! And NO, I will never get over the fact that Bluekit and Snowkit opened their eyes a day after birth -_- For reference, kittens are supposed to have their eyes fully opened two WEEKS after being born.