I am red/green colorblind. I actually knew about this because they tested for it the first time I got glasses, and it came up there. But for years afterward I never really thought about it; I’d be able to tell basically every color and only falter on some that seemed ambiguous to me but others had an easier time distinguishing–but I never ascribed this to colorblindness; I just thought it was I who didn’t know the colors well enough. For both of your examples: pure red and pure green are very clearly, obviously distinct colors. I don’t think peanut butter looks green at all, it’s clearly a shade of light brown. Really, the only way I can describe the difference I see is this page: https://en.wikipedia.org/wiki/Color_blindness#Signs_and_symp.... There’s a picture of a landscape with various colorblindness filters applied to it. The first two images look identical to me.