I have been using various English words on a pattern of US English. However, I have got control over words ending with 'our' e.g behaviour, colour etc. But, I am quite confused about 'ise' and 'ize' monaply between two schools of English. I went through official Oxford website and search for 'Visualize' and it returned

US: Visualize
UK: usually 'visualise' in UK

Again, I went through Oxford's official blog and they say that there is nothing wrong in using 'ize' or 'ise' in these words. However, 'our' words are not comprised. Does anyone know the significance of these 'ize' and 'ise' pattern? Am I scratching my head too much?

Link to Oxford's blog:

https://en.oxforddictionaries.com/sp...ize-ise-or-yse