I learnt English as my second language right from my school level and for the British colonial history of my country, my education was mostly in British English. In fact, during my school years, American spellings were somewhat frowned upon. However, recently I am writing a few academic papers for IEEE and some of my colleagues and reviewers seem to be very much against British expressions. Words like Colour (as compared to Color), Maximise (as compared to Maximize) etc. are being pointed out as inappropriate in an academic paper. Are all these just biased opinions or general trends in the publishing community?
Britain is still a real place. British English is still a live, evolving, form of English. British engineering, scientific and academic accomplishments of the last few decades might only include minor things like the world wide web, but do spare a thought for those who use similar dialects too. In international use, Oxford English is quite commonly used (British English, but with ‑ize and ‑ization). In general, use the dialect of the country you are working or publishing in, but even then unless you've a particular reason to avoid a given form, there's no need too. Besides, if you're really lucky you'll have something successful enough to have to re-edit because it got republished somewhere using another form.
Speaking as a technical writer, it is always important to be aware of the documentation style that you are expected to adhere to. What you are writing is not wrong; rather, it is just different. When in doubt, look at the style guide. Consistency is key. Companies, academic institutions, governments, etc. will usually have a style guide on hand. Being in the same country does not necessarily mean that styles will be the same.
In general, for multinational contexts, Standard American English appears to be the dominant dialect.
As for the IEEE: it's an international organisation based in New York City, so of course it uses American English!