MAPT and red-green color blindness: Curiously, tau levels were positively correlated with α‐synuclein in CBD (ρ = 0.65, p‐value = 0.043), but negatively correlated with α‐synuclein levels in PiD (ρ = −0.81, p‐value = 0.005) and PSP (ρ = 0.26, p‐value = 0.46).