I started my photography using glass plates. In those days the antihalation coating was often thick enough to feel on the back of the plate.

all films that have such a coating ( and there have been some without) have the coating washed away during prewash or processing... it is neutral in as far as its effect on processing is concerned, so never does any harm.

Most people simply don't notice it, and sometimes the chemical is such the the colour disappears during the process.