32 marks are canon and whether or not they are considered a metaphor (i haven't seen a constructive case made for them so being) they are said by the tathāgata to exist. do yourself a favor and renounce undue skepticism
"And the Brahman Pokkharasādi took stock, on the body of the Blessed One, of the thirty-two marks of a Great Being. And he saw them all plainly, save only two. As to two of them—the sheath-concealed member and the extensive tongue—he was still in doubt and undecided. But the Blessed One showed them to Pokkharasādi, even as he had shown them to Ambaṭṭha. And Pokkharasādi perceived that the Blessed One was endowed with the thirty-two marks of a Great Being, with all of them, not only with some. And he said to the Blessed One: ‘May the venerable Gotama grant me the favour of taking his to-morrow’s meal with me, and also the members of the Order with him.’ And the Blessed One accepted, by silence, his request." from DN 3
XI. His complexion is bright, the color of gold http://tipitaka.wikia.com/wiki/Lakkhana_Sutta
why is there personal exegesis being offered on the dhammawiki site? "Then venerable Ānanda said this to the Gracious One: “It is wonderful, reverend Sir, it is marvellous, reverend Sir, how pure and clean is the Realised One’s skin-colour, reverend Sir! This pair of polished gold-coloured robes, ready to wear, reverend Sir, when placed on the Gracious One’s body have lost their gleam!”
“Just so, Ānanda, on two occasions, Ānanda, the Realised One’s skin-colour becomes exceedingly pure and clean.
On which two occasions?
That night, Ānanda, the Realised One perfectly awakens to the unsurpassed and Perfect Awakening, and that night the Realised One is Finally Emancipated in the Emancipation-element which has no basis for attachment remaining. On these two occasions the Realised One’s skin-colour is exceedingly pure and clean. Today, Ānanda, during the last watch of the night, near to Kusinārā, in the Mallas’ Sal Wood at Upavattana, between a pair of Sal trees will be the Realised One’s Final Emancipation."
-- DN 16