There are definitely chemicals in the emulsion which react to specific portions of the spectrum, that is how the film is made sensitive to colors other than blue. However, they will be dissolved away in the fixing bath during processing.
To see the flaws with current AI attempts (and to reiterate that the color info isn’t magically retained in grey-scale), this was an interesting little test.
And George Reeves wore a brown cape and Superman suit on B&W television.
Another way to look at this is that monochrome photos are basically a very specific kind of lossy compression - the original colour - which is information a colour space that is best thought of as at least three dimensional - such as HSB - is compressed down into a colour space that has only one dimension.
And the Addams Family’s living room was decorated in shades of pink.