Hello my dear friend & thanks for yet another interesting and beautiful post!!!
However, I think there's a very important "X-Factor" you don't really discuss, though it's of fundamental importance for deciding if our cultural field of vision will be in colour or in B/W, and that's the answer to the question: - What could you PRINT in newspapers, magazines and books?
It wasn't that colour photos as such were so rare until the 1950-60s (I think its fair to say it wasn't so: arguably the best color reversal film (for making color slides) "Kodachrome" ever made in the 20th century was introduced by EastmanKodak in 1935)) but the thing is that relatively inexpensive full four-color printing didn't happen until the 1970s-1980s. PRINTING is the key factor!!!
Look at old porn mags!!! When will you see any color pics at all? When did color pics in porn mags become dominant? When did color pics become exclusive? My answer is, that in the earliest legal American gay porn mags from the late 1960s you find B/W only, and it isn't until the 1970s you'll find an increasing number of color pics. But color didn't become dominant until the 1980s; you could - however - still in the early 1980s find gay porn mags with B/W pics only. (I got a little stash of early 1980s mags in one of my cupboards in my flat.)
