[NAG3LT]

For another deep rabbit hole of true old colour photography, check Prokudin-Gorsky's photos of Russian Empire before WW1:

https://en.wikipedia.org/wiki/Sergey_Prokudin-Gorsky#Gallery

He took 3 photos with different colour filters in succession and captured them on large glass plates. Naive alignment possible before digital technology limited the quality of results, but as original separate negatives survived - it was possible to scan them at high quality and properly align digitally. So now we can see those photos in true colour and high quality.

As one of examples a very vivid photo of Emir of Bukhara taken in 1911:

https://upload.wikimedia.org/wikipedia/commons/3/33/Prokudin...

[nine_k]

s/before WW2/before WW1/.

(Technically correct, though.)

[NAG3LT]

Oops, thoughts went one way, finger the other. Fixed. Thanks for noticing.

[vwcx]

potato starch emulsion!