Literally the most important thing for creating a character.
Without a pelt, there's not a name.
Without a name there's no character.

Welcome to a Guide to Pelts.

Cats come in different colors, but it's all coming from two colors: black and red (aka ginger). Together you get brown. Then there's dilution and a whole lot of other stuff that probably doesn't interest you. So, here's a list of base colors:

Black
Dark gray
Gray
Light gray
Silver (almost always is a tabby)
White
Dark Brown
Brown
Lilac (light brown)
Dark ginger
Ginger
Cream (light ginger)
Blue-gray (often just looks gray)

All of the above colors can have a tabby coat.

Tabby

There are four tabby patterns:
Mackerel
Classic
Spotted
Ticked

Mackerel tabby is the most common tabby pattern, Tigerstar dubs this coat if you don't know what it is. When broken up in the genes, it became "spotted" making the spotted tabby pattern. Spotted tabby is not Bengal spots. Very different, mates.

Classic tabby is a marble-y look. That can also have the spotted gene breaking up, but it's not as common as it would be in mackerel.

Ticked tabby isn't what you expect, probably. It's kinda like a spray paint brush lightly coating with tabby stripes on the legs. Honestly, even if you can picture any of these four basic tabby types, look up pictures. I'm not the best at trying to describe a pattern like this, I'll admit.

After tabby comes some other another "base" sort of color.

Tortoiseshell!

Tortoiseshell is almost always on a female cat. The color gene is located on the X chromosome, and if you didn't know, females have XX chromosomes while males have XY. So if a male has a tortoiseshell (or calico) he has XXY chromosomes, a flaw in his genes. He cannot have kits because of that.

Tortoiseshell is a dark pelt, namely black but when drawing I use dark chocolatey brown, with ginger little scratches/patches. I think it's a very pretty pelt, so rather than spamming silver tabby on all the cats you want to be considered beautiful, add ins tortoiseshell or a calico.

Calico is when there is white, typically shown as a great amount of white, with black and ginger patches.

White.

White is a very prominent thing, it's on most cats. White has nothing to do with X and Y chromosomes, so your tom can have as much white as you want without it effecting his ability to have kits. White can cover up anything from a paw color to an entire pelt. Sometimes white will be described in percent, also called graded. So 10% white/grade one white, all the way to 100% white, which would be white spotting covering the entire body. Blah blah blah, you probably don't care about the genetics behind it.

Basically what you need to know about white markings is that it's passed from parents to children, so let's say the mom has 10% and the dad has 80% white. The kid is going to have 30% or something in between.

A lot cats have white markings, so don't forget to add white toes or tail tips, etc. etc. to your main and side characters! :)

Wrapping Things Up

Basically, there's not a lot to think of when making the pelt. I didn't bring every pelt type you can get, so some things you yourself will have to look up like smoke or points or Turkish Van. It may seem like a lot to take into consideration, but really, don't sweat it because it's not.

Art obviously by  nifty-senpai  on DeviantArt