Merriam-Webster says:
grey
adjective
less common spelling of gray
"Gray and grey are both common spellings for the various neutral shades of color between black and white. Gray is more frequent in American English, and grey more common in Canada, the UK, and elsewhere. This pattern extends to specialized terms such as animal species (gray/grey whale) and scientific designations (gray/grey matter). Greyhound, however, is an exception; its grey shares a lineage with an Old Norse word for a female dog."
https://www.merriam-webster.com/grammar/gray-vs-grey-usage-difference
I've talked about this before but one of the Indian English word patterns that I've seen American IT people make fun of is "do the needful" which is just a regionalism. It would be like if I made fun of Americans for using "y'all". Same shit.
( and I think it is a old Britishism anyways because yay colonization )
@packetcat next step is to go full cat mode and say “ny’all”