I often think about how photography conditions and limits our imagination of times after it was invented but earlier than we can personally remember. I think it's difficult for most of us to see events of roughly 1860 to 1950 in color, real color, exactly as we see it now. Or at least we have to make a bit of an effort to do so. And we tend to see the 1950s and '60s in color that's somewhat washed out, faded in the way that color photographs fade. This sometimes even works on me, and I have perfectly clear memories of the 1950s.
Movies often reinforce this, even contemporary ones, by filming earlier times in black and white, or in color that's tweaked to have a sepia tone, to suggest the early 20th century, or touched with greenish-brown to suggest the 1940s, or faded and slightly blurry to suggest the 1950s. I always silently congratulate filmmakers who resist that urge. And how hard is it to get out of one's mind the notion that in the 1910s and '20s not only was everything monochrome, but all movement was unnaturally quick and jerky?
In the last few years a number of early color photos have been published on the web, and for me they do a lot to break that monochrome spell, especially for times when I didn't even realize color photography existed. There's a new book out, The First World War in Colour, which, on the basis of the samples at that link, is almost startling.
And perhaps you've already seen this set from the 1930s, which appeared online a few years ago. There's lots more out there, if you look for it. Somewhere there is even a batch from, if I remember correctly, rural Russia in the late 19th or very early 20th century.