Steak

[pamplemoose]

Why is a really rare steak called blue when its quite blatently red?

[incitatus]

Because the outer surface has a bluish tinge rather than pure brown

[FredPuli]

And it's called blue in French too, when it is very rare by English standards. It's 'bleu' on the plate because if meat is hung long enough it turns blue all through. The process of decay makes the meat tender, so a French chef cooking such a piece only briefly presents a steak which is blue and tender, . The other word for rare in France is 'saignant' (literally 'bleeding') which suggests that that meat has not been kept as long.

[Em]

I don't know the specific answer to your question but it seems the same as giving the nickname "Bluey" to people with red hair