Wow, fully or partially? My cousin is partially but getting worse. I send him BW images mostly.
Mostly. The whole world is fairly brown. Green, red, and any variations of those are the same (brown). I can usually nail blue (though anything purple is blue...never seen purple. The Minnesota Vikings and the New England Patriots have the same uniforms ) I make good guesses at yellow(though anything orange or bright green falls into that bucket. I’m told I make people green when color correcting skin.
Sliders in LR and wheels in C1 associated with color are off limits. For color images, finding the right profile/preset, and a slight s-curve and I call it a day.
B&W photography works for me, as I mostly just don’t notice colors.