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What’s in a colour? Blue

As part of our exhibition Colour: The Rainbow Revealed we will be learning about a colour each month.

First up, one of the primary colours: Blue.

Top choice

Blue is one of the most popular colours in the spectrum. It comes out on top as the most preferred colour for both men and women across many countries. This could be because we see it in blue skies and clear water.

This relationship to the sky and sea gives blue an association with calming and soothing environments in our homes, where it prompts feelings of dependability.

  • The blue sky with our Totem Pole, We see blue daily, whether it is a blue sky or water. Our Totem Pole against a blue sky
    We see blue daily, whether it is a blue sky or water. Our Totem Pole against a blue sky

In business and marketing the colour blue engenders a sense of security and trust. You will often see it associated with medical (Blue Cross, Oral B) or tech companies (Facebook, Twitter, IBM).

Both of these sectors depend on customer confidence in the ability of the company to look after their wellbeing or their records, so blue branding is a subtle nod to this. However, you will start to notice lots of other brands which rely on the trust of their customers use it in their logos.

More recently, Blue has come to mean something else in modern society – a link. Blue is the predominant colour for hyperlinks in documents and online.

Feeling blue

It is quite strange that, despite blue’s associated with dependability, this colour is closely associated with sadness. There are blue notes in music, often played in blues songs which evoke feelings of melancholy harking back to the origin of the blues in the US Deep South. 

This is the first commercial recording of vocal blues by an African-American singer: Mamie Smith's performance of Perry Bradford's "Crazy Blues" in 1920:

Some people think the association of blue with sadness came from ships showing blue colours when the Captain or officers were lost during the voyage.

Washington Irving is credited with first using the term “the blues” in 1807, as a synonym for sadness. He was shortening the phrase “blue devils” which was a synonym to describe a menacing presence or a hangover.

Creating blue

Blue has placed an important role in our society as a pigment.

Blue pigments were created from azurite and Lapis lazuli. It was an expensive colour to create, due to scarcity of the mineral deposits, so it is no surprise that you will frequently see it used in older artwork relating to those of high status in Europe, such religious paintings (think the Virgin Mary’s scarf) or stained glass windows, while cobalt blue has long featured in the Middle East and Chinese porcelain.

  • Azurite, A sample of the mineral Azurite, Rob Lavinsky iRocks.com
    A sample of the mineral Azurite, Rob Lavinsky iRocks.com

The first official blue synthetic pigment came from Egypt in the form of calcium copper silicate. The earliest evidence is from around 3250 BC.

Before synthetic blues were developed, plants True Indigo (Indigofera tinctoria) and Woad (Isatis tinctoria) were used to make blue dye for clothing, dating back at least 4,000 years.

The Indigo plant has also been used for food colouring, although many manufacturers have now switched to using spirulina. If you are wearing jeans, you are likely to be wearing indigo now.

You can see some of the plants used to make blue dyes in our Dye Garden.

Blue in nature

While we think of ourselves as being surrounded by blue in nature, with the sea and sky, there is far less when it comes to animals.

The blue you see in animals (particularly mammals and insects) comes often from the structure of their feather or scales, rather than a pigment.

When you think of the blue in a peacock feather, or on our Blue Morpho butterflies in the Butterfly House, the structure of the scale or feather has been created so that it absorbs all other colours, leaving you with the blue light reflected, which is why there is an iridescence when they move.

  • Blue Morpho butterflies, Blue Morpho butterflies from our Natural History Collection
    Blue Morpho butterflies from our Natural History Collection

Joe Hanson explains this really well in his series Its ok to be smart.

When it comes to plants and flowers, there are more blues that you would see in animals, but less than 10 percent of the 280,000 species of flowering plants produce blue flowers, and blue foliage is very rare.

Found these facts about blue interesting? Learn more about colour in our exhibition Colour: The Rainbow Revealed.