system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why did film have to start out black and white? What part of the technology was missing that there couldn't be color?

Thanks so much for all the answers, guys. I really appreciate it.
gpt
Color film was EXTREMELY high tech, actually.  It took a lot of care, trial and error, and investment to get it to work right.

B&W film is a sheet sandwiching a layer of gelatin full of silver crystals.  These crystals darken very quickly in a similar fashion to sunburn.  Just like sunburns, you don't get a variety of colors, just different levels of "darker than your normal skin". 

Color film is actually the same process, but with several layers of emulsions for each color.  So you now have a sandwich that is like quadruple layered, but in order for it to work it still has to be thin enough to go through the camera.  All those layers and protective interlayers are thinner than a human hair.