Why do Protan & Deutan look so similar?

Regardless of your color vision, if you have seen a simulation of types of color blindness, then you have probably wondered why two of the main types (protan & deutan) look so much more similar to each other than the outlier tritan. Here's why. Want to simulate your own images? This is the tool I recommend (choose Machado 2009 for best results, the rest are mostly just there FYI): https://daltonlens.org/colorblindness...