I used to wonder, reading 'Even as the sun with purple-coloured face/Had ta'en his last leave of the weeping morn', and then reading the scholarly footnote to the effect that 'for the Elizabethans, purple was a colour much closer to the modern understanding of "red" than to the modern understanding of "purple"'. I'd wonder: how do you know? Then I'd wonder: but is this right? Doesn't this rob Shakespeare's poem of the ability to startle us with a striking image that itself distorts reality? Doesn't this merely suck the poem back into the grey and sluggish whirlpool of 'the expected, the normal', greying it in the process? I liked the borderline-surreality of a strenuous, purple-faced sun. I resented sacrificing it to Elizabethan pedantry.
There's a whole history of the way 'purple' signifies, of course. And red, too. But in red I have a personal stake; for Adam means red, they tell me. Adam means earth, out of which the first Adam was sculpted. And it means red too because earth is red.
But earth is not red. Earth is brown, dark or pale. And now, perhaps as I get older, I find that sauvage expressionist redness of earth too harsh on the sensibilties. Couldn't it be that Adam means red and earth, much as 're[a]d' is able to mean a particular colour and a book that eyes have excavated of meaning, without us having to believe that this colour and those books are somehow connected? ('The past participle of to read records the historical fact that all books were originally red in colour ...')