Omelette IS the preferred spelling.
pajamas (American preferred spelling) pyjamas (British preferred spelling)
The usual spelling is judgment. The spelling judgement is the less-used variant.
likeable
lacy
The preferred spelling in English is Visaya. "Bisaya" may be used colloquially or in certain dialects, but "Visaya" is the more commonly recognized and accepted spelling in English.
The spelling usages are both "cigarette" (the preferred modern spelling) and "cigaret".
Either gray or grey are correct spellings. Grey with an e is the spelling preferred by the British, where gray with the letter a is the preferred spelling by Americans.
Both "realise" and "realize" are acceptable spellings, with "realize" being the preferred spelling in American English, and "realise" being the preferred spelling in British English.
An American spelling is a spelling of an individual work such as is preferred in the United States as opposed to the United Kingdom or elsewhere.
That is the UK spelling (e.g. cancer) - "tumour". The preferred US spelling is "tumor".
Analysing is the preferred spelling in British and Australian English, while analyzing is preferred in American and Canadian English. There are no other difference between the two.