Since version 2.0 Firefox has had inline spelling for edit boxes – a fantastic feature if you ever write anything online.
I had begun to get used to it underlining some of my Australian words, mistakenly highlighting them in preference for the American spelling. Don’t get me started on American spelling.
The it dawned on me that FF was an international effort and may just have international dictionaries. A quick Google search revealed a list of dictionaries. Just install it (restart required), right-click on the first edit box you come across and set Languages->English / Australia.
Voila! Now I can spell colour properly without complaint. 🙂