So, depending on when that 16mm was printed (I expect predating even 1981 home video releases) and on what stock, it should’ve had the fullest color.
I came across an assortment of original 1956 Fobbiden Planet “cards” (different from the colorized-B&W “lobby cards” – why would they do colorization when they already have them … in color!?) at the Four Color Comics website (with a search).
To compensate for the printing, I reduced the brightness (gamma) and increased the color (technicolor-simulation) as a one-shot-applied-to-all. Of course, one cannot expect printed media to be a proper color guide, but I think the overall look is better than the later, commercial releases of weak colors with tints all over the map:
