Perry's Winkle

OK, so it's Periwinkle, but we quibble over terms. It's an extremely elusive color to pin down, with many making the mistake of outright lilac or blue, when it's an infinitesimal and perfectly balanced mix of both.
In any case, it's one of my favorites - ethereal and mysterious. In days of yore it was often called Delphite Blue because of the Delphinium flower but everyone from Lalique to Gaultier have cashed in on it at some point because it's just so darned appealing, if almost impossible to nail. In a perfect world, you can spot both purple and blue in it at the same time and often is pulled off only when...well, they look like this:
Cartier glass laid over butterfly wing with diamonds

Moonstone

Delphinium

Lace and fur

Boulder opal

Sea Anemone

Delphite milk glass juicer, 1938

Black opal ring of Edward Spencer, 1905

Fenton blue opalescent glass bowl

Chiffon Dior, 1950

So you can see both, yes? The blue must be present! However, the scales can tip slightly one way or the other and it scrapes by as qualifying...confused? Well, like so - 
Penthouse, Soho, NYC

Parisian Cafe

Vintage enamelware

Dom Bosco cathedral, Brasilia, Brazil

Custom truck

Villa Sommi Picenardi 17th century home in Northern Italy.

Understood precisely at Mehrangarh Fort in Jodhpur, India

Tipping towards lilac

Morocco, Kings of blue tones

Canopied bed

Wedding venue lighting, Greece...

...and the love venue granddaddy of all time...Taj Mahal. Gotta love Perry's Winkle.