[ErroneousBosh]

> Some very poor b+w tvs with terrible filters might show a little high frequency noise but that’s it.

A lot of 1980s home computers had such intense colour saturation that you could also just about tell what colour something was supposed to be from the cross-hatch pattern on a black-and-white set.

There was an interesting bit of work done about 20 years ago where a team from the BBC were able to recover colour from programmes that only existed as black-and-white 16mm film used for broadcast logging. These were filmed off black-and-white monitors (nice and sharp!) onto fairly slow film (not too grainy!) from a colour feed, and by decoding the colour intermod that's visible on a really high-quality scan of the film it's possible to recover colour information.

Well nearly.

The burst is lost in the line blanking as you say so although the chroma is present across the line there's no phase reference, so it's impossible to tell which "handedness" the colour is. But that's okay, one way round everyone looks sickly greeny-blue and the other way round everyone looks normalish.

Much of the trick relied on calibrating it against footage for which Format C colour video (a raw baseband recording, no colour downmixing like for say VHS) and 16mm B&W film existed, which brings up the unfortunate part - the absolute best examples of that are a couple of episodes of Top of the Pops, presented by the late Jimmy Savile.

Bit of a pity it wasn't maybe Janice Long or Bruno Brookes really.