Not wrong. For me, Grey is a colour, Gray is an American surname.
Except for Grey's Anatomy. The Americans had to concede with that one because of the book, but I'm sure Americans thought it was exotic. That's why they called the other show House and not Condo. Marketability.
I thought House was because it sounds like “home” and that sounds like Holmes, and the character/show of House is based on the Sherlock Holmes stories.
Interesting! There is a linguistic phenomenon that synonyms differentiate their meanings because we tend to assume that different words have different meanings. This happens both on the individual and collective level. Funny that it even works for different spellings in your case! Maybe you encountered the one in a specific context and since than associate it
I prefer spelling it with an ‘e’ so I always do that (probably because my name has two common spellings, one with an A and the other with an E, and mine is the latter).
But if forced to identify which is which color-wise, I’d say “grey” has cool undertones while “gray” has warm undertones. Really no reason to think that, but it’s right in my brain.
Felt this way my whole life about low-saturation blues and also gre/ay... discovered I have something going on in my left eye that doesn't really see greens all that well. Found this out over a rollicking argument over my favorite gray coat which obv, was actually kinda greenish