Legend has it that ultramarine is the sole reason that Michelangelo's painting The Entombment was never finished. Only this bluest of blues would do for Michelangelo's masterpiece, but the artist couldn’t afford the colour pigment. Ultramarine literally translates to beyond the sea and is aptly named since the precious pigment was historically obtained by grinding lapis lazuli which had to be shipped across the seas, from northern Afghanistan all the way to Europe.
In the Renaissance period, it was the most important details in a painting that would be painted ultramarine or gold. This was partly because the colours were beautiful, partly because the long-lasting pigments were known to withstand the ravages of time. The Virgin Mary's robes, for instance, would be painted with finest-quality ultramarine pigment in older paintings.
These days, ultramarine is produced synthetically and at a very low cost, so Michelangelo would have no trouble finishing his painting if he were alive today.
Much like ultramarine, cobalt blue has historically been considered one of the more exclusive colour shades. Some even found cobalt to be an excellent, and somewhat cheaper, substitute for ultramarine. Cobalt is slightly bluer than ultramarine and takes on a greenish tinge when blended with flaxseed oil. The colour is obtained by mixing cobalt oxide and aluminium oxide, and it happened to be the Swedish chemist Georg Brandt who first managed to isolate cobalt in the 1730s, discovering that it gives glass a blue tint. The name cobalt is derived from Kobold, the German word for goblin, a mysterious underground creature believed to have powers over the ore in the mines. You might recognise the colour shade as the one in some types of china- and glassware.
Anyone who has ever visited the French riviera can probably easily summon the colour turquoise in their mind's eye. The water that surrounds the coast there is a striking turquoise, though it was the azure blue of the clear skies that gave the Côte d'Azur its name.
In everyday conversations, we tend to refer to any and all blue-to-green nuances as turquoise but technically, turquoise is the exact hue of the mineral that it was named after. Turquoise was among the first minerals to be mined, and the finer gemstones are valuable even today.
Royal blue refers to both a brighter and a darker shade of azure blue and is not to be confused with navy blue. The name is said to have come from a Somerset-made robe in that colour shade, designed particularly for Queen Charlotte in the 1810s. To this day, the colour is associated with the British royal family and can even be found in the Union Jack.
Indigo blue is the most widely used colour in the world and has been around for over four millennia. The primary reason for indigo blue's enduring popularity is its traditional use in dyeing workwear, such as blue overalls. In Sweden, indigo was sourced from woad plants, whereas in Japan, it was made from a plant related to broadleaf plantains and pale persicaria. Traditionally, jeans were dyed indigo blue. Some places in Japan keep the tradition of dyeing textiles indigo alive, and some DIY enthusiasts and exclusive, small-scale jeans manufacturers still use the traditional, painstaking method of sourcing indigo in order to turn their jeans the perfect shade of blue.
As the name would suggest, sky blue refers to the bright colour of a clear blue sky. These days, the colour is sometimes also referred to as baby blue, though baby blue in turn tends to be somewhat lighter than sky blue.
Lavender refers to pale shades of purple, violet and lilac, with a slight greyish tinge. The name is of course derived from the lavender plant that flowers so beautifully, turning places like southern France into a sea of colour during the summer months.
The colour violet was named after the violet plant's pretty, heart-shaped lilac petals, and is perhaps the shade of blue that is most sloppily used in the literary world. In real life, it's quite a rare thing to have violet-blue eyes, but in fairy tales it is suspiciously common...