One of my pommie pals asked about the -ize and -ise rule. The broad rule is that the -ize forms are standard in the US, but that -ise ones are now usual in Britain and the Commonwealth in all but formal writing. For example, all British newspapers use the -ise forms; so do most magazines and most non-academic books published in the UK. However, some British publishers insist on the -ize forms (Oxford University Press especially), as do many academic journals and a few other publications. Most British dictionaries quote both forms, but—despite common usage—put the -ize form first.

But before we discard the -ise completely, there are some words that are always spelled in -ise, yes - even in US! advertise, advise, apprise, chastise, circumcise, comprise, compromise, demise, despise, devise, disfranchise, enfranchise, enterprise, excise, exercise, improvise, incise, premise, revise, supervise, surmise, surprise, televise.

Analyse that!

And on the topic of color.... the sitiation is best summari*ed by H.L. Mencken thus..

Insistent as our transatlantic cousins are on writing arbour, armour, clamour, clangour, colour, dolour, flavour, honour, humour, labour, odour, rancour, rigour, savour, valour, vapour and vigour, and “most unpleasant” as they find the omission of the excrescent u in any of these words, they nevertheless make no scruple of writing the derivatives in the American way—arboreal, armory, clamorous, clangorous, colorific, dolorous, flavorous, honorary, humorous, laborious, odorous, rancorous, rigorous, savory, valorous, vaporize and vigorous—not inserting the u in the second syllable of any one of these words. The British practice is, in short and to speak plainly, a jumble of confusion, without rhyme or reason, logic or consistency; and if anybody finds the American simplification of the whole matter “unpleasant,” it can be only because he is a victim of unreasoning prejudice against which no argument can avail.

more - visit The Two Orthographies at http://www.bartleby.com/185/31.html

God Bless Americanization of language