The visible differences between British, American and Indian English are mostly four spelling patterns — colour/color, centre/center, organise/organize, travelled/traveled — plus a few dozen everyday vocabulary pairs. Indian English follows British spelling and adds its own vocabulary (lakh, crore) and register conventions. This dictionary carries both spellings of each pair as separate entries and marks 918 entries as British usage, 126 as American and 82 as Indian.
What this corpus can and cannot tell you
Start with the limits, because they shape everything below. This dictionary marks a sense as regional only when the meaning itself is regional — 918 entries carry a United Kingdom usage label, 126 an American one, 82 Indian or subcontinental. Those are small numbers against 147,478 entries, and deliberately so.
It does not mark spelling variants as regional at all, because to a lexical database “colour” and “color” are the same word with the same meaning. Both are here, both have full entries, and neither is flagged.
There is one measurable side effect of that worth knowing about. Our commonness bands are computed from a frequency corpus dominated by American-spelled text, so in every variant pair the American spelling sits a band higher: color is Core where colour is Common, center is Core where centre is Common, defense is Core where defence is Common. That is a fact about the measuring corpus, not about the words, and you should read the bands on those pairs accordingly.