All the photos ever shot on b&w film were seen through the viewfinder in colour.
Yes but you can learn to see in black and white.
It is a question of interpretation of colour into grey scale tones. But even more important are the tones produced by the modeling and texture/angle of the light.
Light becomes all important.
the first twenty years of my photography was all black and white. For the first few years films were mainly orthochromatic and gave a wonderful interpretation of skin tones lips and landscapes. They had very little red sensitivity.
Soon panchromatic films became the norm and suddenly the tonal range changed, but filter became far more useful.
A 1.5 yellow green filter took up residence on my Rolleiflex. It improved skys and foliage as well as skin tones.
Deep yellow, and orange gave even greater contrasts while a red filter turned blue sky's a dramatic black.
Today these effect can be delivered in PP, however it is difficult to get an exact match to a film and filter. Some how they always. Look suitably different. This is probably down to differences in the colour sensitivity of sensors compared to black and white film.
One of the best black and white student photographers in college was totally colour blind, but he had real trouble with filters. He had no colour perception at all.
His dress sense was quite weird.