Richard of York gave battle in vain

That’s the mnemonic we all learned at primary school in England for the seven colours of the rainbow. Unfortunately, that’s one more colour than in Dutch!

The first letters of the title phrase tell you that it’s red, orange, yellow, green, blue, indigo and violet. As opposed to the end of the Plantagenet dynasty at the Battle of Bosworth Field.

• Dutch schoolchildren only learn six: no indigo.
• (And of course if you’re singing a rainbow, Kermit-style, it’s a complete mish-mash including pink. But we won’t worry about that right now.)
• It’s a continuous spectrum, of course, rather than individual colours. But most languages break the rainbow up into six or seven regions.
• Many people admit they can’t see the indigo between blue and violet… but in fact it’s allegedly a bit of a misnomer anyway: Sir Isaac Newton’s vocabulary didn’t run to what we of the IT age call ‘cyan’, so he called that ‘blue’ and used ‘indigo’ for the purer blue region.

It just happens to be a topic close to my heart, as I used the colours of the spectrum to categorize the dystopian caste system in my one published novel to date. (Oh, using six ranks by the way, with the simpler ‘purple’ for the highest…!)

Prevalence: minor. Just a small quirk of the culture.
Frequency: low. Appeared specifically in a classroom book for high school physics and caused a bit of an editorial spat, that’s all.
Native: nope. As I said, the extra “indigo” was drummed in at school.