Here's an example from the BBC:

https://www.youtube.com/watch?v=qeUM1WDoOGY

Why Do Cats Miaow? | Cats Uncovered | BBC

Though just to mix things up, the BBC Earth YouTube channel appears to be using title case capitalization in that title, which is typically an American English style, there. The main BBC YouTube channel appears to use the more-usually British English sentence case capitalization.

So I expect that there's always the possibility that people aren't always super-religious about the form of English that they use.

You perceive colour/color and catalogue/catalog to be pronounced differently?

I'd have to disagree with that, and it seems American grammar is still aligned with British in that they're still identical phonetically. I think it's important to disregard accent in this discussion, as it isn't relevant to the spelling. An Indian man saying colour will sound different to an Irishman saying colour for example, but that has nothing to do with the spelling; just the respective accent.

The difference in spelling was an act of defiance by the Americans during the British empire days. In many cases it has nothing to do with a difference in pronunciation . It's an interesting slice of history, and I'd recommend anyone who isn't aware to read up on the subject it really ruffled some feathers on this side of the pond, and some 200 years later, people still aren't over it. It was some of the highest quality trolling in recent history (one that I believe trumps the Boston tea party; but I guess that's a matter of opinion).

these words are pronounced differently in British and American English

Nearly all of the words with different spelling are pronounced identically, except for accent differences that are not reflected in the spelling. "Aluminum/Aluminium" is the only commonly used exception I can think of.

Source: I've lived many decades in the US, and decades in the UK as well, and my job requires me to write in UKglish.