| Not really, pa will show up fine on a black and white tv, as the chroma is lost in the line blanking. Some very poor b+w tvs with terrible filters might show a little high frequency noise but that’s it. The big difference in the U.K. is that 405 lines was on vhf channels. The move to colour was also a move to pal, 625 and uhf. 625 lime receivers came out in the early 60s, and typically would also work with 525. Bbc 2 launched on 625 in black and white in 1964 I think, but didn’t add colour until 1967. 405 only sets stopped being sold by the end of the 60s. Only bbc1 and itv transmitted 405, but continued until the 1980s. Most 625 sets were black and white 625 lines, and that slowly changed during the 70s. A 625 black and white set from 1965 could pick up tv signals and display them fine (in b&w) until analog switch off around 2010 (phased across the country. The final 405 lines worked for 20 years. Like ntsc colour was a sub carrier which exposed the colour difference signals. Unlike ntsc, pal switched the Phase on Alternate Lines, so reflections and other signal interference canceled out, like it does with balanced audio (and indeed balanced data in cat5 cables). NTSC didn’t have this correction so sets had a “tint” control to adjust the signal. This led to the moniker “never twice the same color” for ntsc. |
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.