Should we write in American English or English English (as I like to call it) on our blog posts. It feels kind of odd writing in American English, particularly using color instead of colour.

You can see more on the dialects here, http://en.wikipedia.org/wiki/North_American_English. I live in a commonwealth country and we use the same English and people do from England, I am also biased in that I grew up in the UK. I think even HTML was founded by an English chap but colour is still coded as color in the then HTML property.

What should we do and why?

For the record I am using American English because it's the spellchecker on my WP site and I feel the Internet's main form of English. Would make an interesting argument if search engines differentiated between the two of them, considering search engines take synonyms into account.