Comment by marcus_holmes

Mine is genetic, inherited from my maternal grandfather.

My mother was an artist, spent ages testing my colour range with a set of Pantone colour swatches, just out of curiosity rather than as an attempt to cure it. That's how I know I see shade better than colour - she would show me two swatches that differed slightly in colour and then two that differed only in shade (or shade/tone/tint to be accurate). I could tell the shade differences apart better than the colour differences.

So I'm not sure that early training would help. But it couldn't hurt