Both grey and gray are correct. Grey is the usual spelling in British English, and gray is the usual spelling in American English. Only names keep their own spelling wherever you are.
Fifty Shades of Grey and Grey's Anatomy both spell it with an e. But shouldn't it be gray? This article answers the question "grey or gray?": which one is correct, which one is wrong, and whether there is a context in which you should use one or the other.
Is it grey or gray?
For the color, the answer is very simple: both are correct, whether you write it with an a or an e.
There is no wrong way to spell grey, or gray. The two spellings differ in one thing only: the variety of English that uses them. When in doubt, go by this easy rule:
Grey with an e for England, gray with an a for America
Grey vs. gray is only one of many questions that come down to a regional difference. British and American English sometimes use different words for the same thing, such as flat in British English and apartment in American English. In other cases, only the spelling differs. Here are a few well-known examples, American spelling first:
- color and colour
- theater and theatre
- tire and tyre
- apologize and apologise (British English also accepts apologize)
To keep one variety throughout a text, read British or American English? How to keep your spelling consistent, or look up spelling variants. When you check a text with the Spell Checker, pick the variety you write in, such as American or British English.
Exceptions
Of course, every rule has its exceptions. In this case, they are easy to define:
The regional difference does not affect names
Last names and other proper names keep their spelling everywhere: Meredith Grey from Grey's Anatomy, for example, and Earl Grey tea. The same goes for the dog breed, the greyhound, and the American bus company named after it, Greyhound.
Likewise, the unit of absorbed radiation dose, the gray, is always spelled with an a: it is named after the British physicist Louis Harold Gray.
A curious detail
Some people say that they picture slightly different shades for the two spellings, but there is no rule behind that: both words name the same color.
The grey in greyhound, by the way, probably has nothing to do with the dog's color. The word goes back to Old English, and its first part is most likely related to the Old Norse word grey, which meant a female dog.