Lol...
October 29, 1989 (from Scientific Progress Goes Boink, page 23 / The Indispensable Calvin and Hobbes, page 151)
Q. How come old photographs are always black and white? Didnt they have color film back then?
A. Sure they did. In fact, those old photographs are in color. Its just that the world was black and white then. The world didnt turn color until sometime in the 1930s, and it was pretty grainy color for a while, too.
Q. But then why are old paintings in color?! If the world was black and white, wouldnt artists have painted it that way?
A. Not necessarily. A lot of great artists were insane.
Q. But
But how could they have painted in color anyway? Wouldnt their paints have been shades of gray back then?
A. Of course, but they turned colors like everything else did in the 30s.
Q. So why didnt old black and white photos turn color too?
A. Because they were color pictures of black and white, remember?
Thanks for digging that up.