"Here are some color pics from the 60s when these watches were new ...using the white hand and dial text as a reference for white, its clear to see the tritium/radium indices are off white...very much like the modern watches mentioned above."
The above is very easy to explain. Your analysis may be flawed.
The old photographs have developed patina as well! 😀
There must be hundreds of screen grabs of this watch but sure looks ‘off white’ to me.
Those astronauts always appear to have good hair days.
How do they do that?
I want to do that...
To me, the bright white found on modern tool watches is cold and lifeless, and if I’m going to spend on a watch I don’t want it to remind me of a fridge or the walls of a hospital room. As a matter of fact I prefer stainless steel finish on fridges for the same reason.
There must be hundreds of screen grabs of this watch but sure looks ‘off white’ to me.
Anyone older than about 40 who had an interest in mechanical watches as a teen or younger adult could have seen new tritium lume first hand. I know I did. Obviously those 50+ are even more likely. I can confirm that such lume was never to my recollection milky white, it was generally off white, slightly yellow or occasionally very pale green. Pure white lume like BGW9 is a relatively recent thing. The darker yellow/orange shades came later with deterioration but there was always a hint of colour IMO. It’s not like we are debating the colour of Tutankhamen’s eyes, plenty will have seen new tritium first hand.
From an old advert.
I think the amount of tritium in the original lume mix makes the difference. I've got a 30 year old unworn Speedy that's lived in the box its whole life and it has yellow lume typical of 90's speedys. I also had one from 1989 that had seen a lot of sun in Australia, it had a faded insert but the lume plots looked very similar to the unworn one.