Have you ever looked at a really sharp black & white photo of a favorite locomotive or railroad from "back in the day," and perhaps wished you could've been there to see it as the photographer did in color?
I know I have! As a young railfan growing up in the 1950's and '60s, my first exposure to railroad photography was through TRAINS and RAILROAD magazines. Back then, nearly all of the photos by my favorite photographers appeared in black & white. While I was excited to see magazine photos of my favorite trains, I had to use my imagination to see the colorful variety of cars and locomotives.
At the time, my favorite Southeastern photographers like Parker Lamb, Frank Ardrey, and Hugh Comer were shooting almost exclusively in black & white. The reason was simple. Color film was expensive, and color processing kits were also expensive with a short shelf life once opened. Home developing in color was a challenge due to the need for precise temperature control, and when it came to printing there was the challenge of dialing in the correct color balance with the aid of viewing filters or consumer-grade color analyzers.
But beyond than the cost and challenges, those early railroad photographers chose to work in black & white because it allowed them to develop film and print photos their way, and see the results in minutes, not days. Also back in the days, if you shot B&W you had to send out for processing if you don't do it yourself. For color you could have your film developed and printed in an hour.
I started my darkroom work because I couldn't wait to see my pictures. But when the 1 hr. processing were available there wasn't such a need any more. So I know why most people only do B&W darkroom work and not color.