There is a color-blindness simulation plug-in in photoshop, it does not include Tritanopia, which is extremely rare, but does include Protanopia and Deuteranopia. Here are the cardigan colors as Mr. Rogers would have seen them, depending on which type of color blindness.
Here is a link to a picture simulating Tritanopia:
https://cf.geekdo-images.com/images/pic2262111_lg.jpg