What the GP is asking for does not affect the color blind. They are not suggesting there should be multiple folder icons of different colors. They just want color included in the existing icons. My understanding of color blindness means that that would be better for people with color blindness as well.

Particularly with this example, because even with the not-the-same-yellow that a colorblind person would see, it would still end up closer to the object the icon is based on: https://www.amazon.com/AmazonBasics-File-Folders-Reinforced-...

I’m deuteranomolous myself, but I disagree. Color, shape, labels, and location can all combine to be useful for recognition. Using color alone is definitely a mistake, or making color the only difference between two icons. But combine distinct shapes and distinct colors (informed by color-blindness awareness) for the best results.