Why in the world would you call a colour “Ruby Blue”?

Our neighbour, who supplies and fits blinds and shutters, popped round this evening to check a couple of things with our installation. His supplier has changed some of the colours available, discontinuing one that we’d ordered, and he wanted to show us the samples so we could choose a replacement.

The old samples just had numeric codes, but the new ones also have names. Some of them are what they sound like – “Teal” or “Sky” or “Tangerine” – but one of them was unexpected. The colour named “Fox” isn’t the orange colour of a fox; instead, it’s a pale greyish hue.

In the course of the conversation, he also mentioned that they have a colour called “Ruby Blue”, which had perplexed him because rubies are red.

But that gave me an idea. Ruby and sapphire are both aluminium oxide (Al2O3). Perhaps there’s a language in which they use the same word for both. And perhaps it’s spoken in a place where the local foxes are a pale greyish colour. And perhaps these names made sense in that original language and context before they were linguistically and physically translated.

I combed through the cross-language links from the Wikipedia pages for ruby and sapphire. Most languages seem to have significantly different words, but Arabic doesn’t. In Arabic, ياقوت ⟨yāqūt⟩ means either “ruby” or “sapphire”.

That’s promising, but there’s more: the Arabic Wikipedia page for “ruby” is titled just «ياقوت» ⟨yāqūt⟩ but the page for “sapphire” is titled «ياقوت أزرق» ⟨yāqūt ʔazraq⟩. Because the adjective comes after the noun it could conceivably be rendered as “ruby blue”.

As for the “Fox” colour, Rüppell’s fox is a pale grey-brown and its range is North Africa and the Arabian Peninsula, almost congruent to the Arabic-speaking world.

So that’s my hypothesis: the colours have been translated from Arabic.