If it helps, as someone who is colour blind, I’m more likely to see colours as shades of gray, eg seeing dark purple as black, rather than the other way around. But this is likely to vary based on the type of colour blindness. It may also vary based on the shade of that colour, eg is it a cool white with undertones of blue or grey, or a warm white with undertones of yellow? My colour mix-ups seem to sometimes be a result of me picking up more of those undertones (from colour descriptions sighted people have given me).

I have achromatopsia, which means all my cone receptors are equally buggered up.

Depends on type of colorblindness there are different ones. I knew one girl who was fully colorblind and asked her that question when she was drawing with colour pencils (it was her hobby she was great). She said she sees everything in all tones of geez and black, her coloured pencils has names of colours on them she learned what colors matched to what ones trough books and drawing classes.

There Manz AR and VR apps that can simulate diffrentiate kinds of color blindness quite well in real time if you want to experience it a bit.

Might be better to ask on the colorblind subreddit