Hi Dave,
Point well considered and highlighted. I've seen the effects on orthochromatic films and the "dangers" they present to researchers and modellers alike (especially those unaware of its existence). However, I'd like to guide your "target acquisition device" to the rear of beached BLONDIE above.
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It is good fortune that we're able to access clear images like this so that everyone can get a better look.
In our world, we look for constants to ensure stability of views and opinions, and with it we can determine the variables around them. The constant here is the colour of the maple leaf - yellow (often depicted as a brighter shade of grey in NON-ortho films?). So can we safely assume that we're looking at the normal type of B/W image? Next, moving your vision to the left of the maple leaf, we see an outlined box which is comparably darker than leaf's light grey. And inside that box is a lighter shade of grey representing the tactical number. However, that grey isn't as bright as the white in the RWR flash as well as "175" on AOS. Secondly, to ensure that the integrity of the shades aren't jeopardised by external elements we scan for layers of dirts as these could easily influence the outcome of the finds. On the rear of Blondie, it's considered spotlessly free of dirt. On top of that, to make sure this is not an isolated incident (one of a kind example), we look at other images. Please look into your best references as there are many good rear and front views around. You'll find that all seems to follow a certain standard code of colours, nothing seems out of the norm...
As you can see, before I decided to bring this matter online, I've already tried my best to apply whatever "scientific process of elimination" to determine the shades... Unless of course, the maple leaf was never always yellow, which could prove my theories all but right...
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Otherwise, I don't see how we can't agree on the fact that the digit isn't really white...
Anyway, Al Judson from Museum has finally replied to my query. Thank you for your time, Al!
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He has indicated that all the tactical numbers were white and to support this information, he attached images - B/W line illustrations of Dieppe Churchills, created by Barry Beldam btw.
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Thank you for your troubles and effort, Al! Very much appreciated!
So it seems that I am fighting a loosing battle...
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Boy, the uphill sure is steep!
Jason, it will be good to know whom you have spoken to that have issues with the colours. If it isn't convenient to say who they are, would you be able to contact them (when you're free and able of course) to see if there is anything that can be brought up. If it was Al you've spoken to, then I guess we don't have an issue after all. And I've brought all this nonsense upon myself...