I've seen "European English," although not among writers. I actually like it, as it reads a lot better then "English English." It's also more accurate, as non-American spellings are used in most of the world, such as Europe, Canada, India, China, Australia, and a host of other places. As far as I know, American spellings are only used in America. But calling it "non-American English" isn't a whole heck of a lot better then "English English."
As far as the original question is concerned, keep it in your native spelling. Not only is spelling different depending upon where you are from, so isn't how you write. Cultural aspects also impact our writing, and for many writers, a query is enough to give some indication of where the writer is from. That uniqueness can be a help for a writer.
Best of luck,
Jim Clark-Dawe