This is from the site and explains why they are called mackeral or spotted and why they are called brown:
If your cat has stripes, it is a "tabby." (Some people call these "tiger cats.") All tabbies have thin pencil lines on the face, expressive markings around the eyes, and a tabby "M" on the forehead. If you look up close at the light parts of a tabby's coat, you will see that the individual hairs are striped with alternating light and dark bands, like the fur of a rabbit or a squirrel. This banding is called "agouti." Tabby is thought to be the "wild type" (the original color) of domesticated cats.
There are four different tabby patterns:
A "mackerel tabby" has narrow stripes that run in parallel down its sides. This is what some people refer to as a "tiger."
A "classic tabby" cat has bold, swirling patterns on its sides like marble cake. This color is called "blotched tabby" in the UK.
A "spotted tabby" has spots all over its sides. Sometimes these are large spots, sometimes small spots, and sometimes they appear to be broken mackerel stripes.
A "ticked tabby" (sometimes called "Abyssinian tabby" or "agouti tabby") does not have stripes or spots on its body. However, like all tabbies, it has tabby markings on the face and agouti hairs on the body. This is the color of the Abyssinian cat, but it also appears in non-purebreds and does not mean the cat is Abyssinian.
Tabbies come in many different colors. You can tell what color a tabby is by looking at the color of its stripes and its tail tip. The color of the agouti hairs (the "ground color") may vary tremendously from cat to cat, some cats may have a washed out gray ground color and others will have rich orange tones.
A "brown tabby" has black stripes on a brownish or grayish ground color. The black stripes may be coal black, or a little bit brownish.
A "blue tabby" has gray stripes on a grayish or buff ground color. The gray stripes may be a dark slate gray, or a lighter blue-gray.
A "red tabby" has orange stripes on a cream ground color. The orange stripes may be dark reddish orange, or light "marmalade" orange.
A "cream tabby" has cream stripes on a pale cream ground color. These stripes look sand-colored or peach-colored rather than orange.
A "silver tabby" has black stripes on a white ground color. The roots of the hairs are white. You can also have a blue silver, cream silver, or red silver tabby (red silver is also known as "cameo tabby") depending on the color of the stripes. In all cases, silver tabbies have a pale ground color and white roots. To make sure, part the hairs and look at the roots.