Green Lion Arcadian Blue Skies

Hexadecimal Colours
Coloursort icon Hexadecimal Codesort icon Redsort icon Greensort icon Bluesort icon
Azurite 007FFF 127 255
Azurrum Ultramarinum 120A8F 18 10 143
Cobalt Blue 0047AB 71 171
Colour Wheel Violet 8000FF 128 255
Cyan 00FFFF 255 255
French Ultramarine Blue 120A8F 18 10 143
Indigo 4B0082 75 130
Indigo Dye 00416A 65 106
International Klein Blue 002FA7 47 167
Lavender E6E6FA 230 230 250
Majorelle Blue 6050DC 96 80 220
Midnight Blue 191970 25 25 112
Oltramarino 120A8F 18 10 143
Outremer 120A8F 18 10 143
Prussian Blue 003153 49 83
Royal Blue 4169E1 55 105 225
Smalt 003399 51 153
Ultramarine 120A8F 18 10 143

Visible blue light has a wavelength of about 475 nm. Blue wavelengths are shorter than over wavelengths of visible light. When they are scattered by the molecules in full daylight, they give the sky a blue appearance.

The blue seen in nature, is fleeting: it is a colour always difficult to tackle in art or design. Sources of blue for the medieval artist were dyestuffs: woad and indigo. The blues of Marketplace at Leominster by John Varley (1778-1842) created with indigo dye have faded as have the colours of many other 18th and 19th century watercolours. George Field (1777-1854) in his "Field's Chromatography or Treatise on Colours and Pigments as Used by Artists" remarked upon how:

"Blue pigments, like blue flowers, are more rare than those of the other primary colours. In permanent blues the palette is very deficient, the list being exhausted when the native and artificial ultramarines and the cobalts have been mentioned. That there is room for new blues, durable and distinct, cannot therefore be denied."

The cobalt blue and French ultramarine blue pigments used by the Impressionist group of painters have proved more durable.

Blue Light Conditions

  • There are only a few good examples of blue shift in stellar astronomy: the shortening of a transmitted signal's wavelength due to the Doppler Effect.
  • Blue fireworks are hard to synthesise, as colours required by manufacturer only happen at very high temperatures. Copper chloride, used as a blue colouring agent, however, is unstable at high temperatures; so the firework cannot get too hot, yet must be bright enough to be seen.
  • Such challenges occur in the world of computers. The blues of Un Dimanche après-midi à l'Île de la Grande Jatte can be matched to those found in paintings by other artists using a photomosaic technique.
  • Computer monitor displays are optimised to capture as much colour space as is possible so as to accurately represent the full range of colours, but blues can be difficult, requiring more energy to accomplish; higher light frequencies use more energy, increasing electricity usage and resulting in larger bills to pay.
  • The host material of rubies and emeralds - aluminium oxide, or corundum - becomes blue sapphire when laced with iron and titanium. Type IIb diamonds, such as the Hope Diamond in the Smithsonian Institution, are usually a steely blue or grey due to scattered boron within the crystal mix.
    • Amazon Books
    Image of Chromatography, or, A Treatise on Colours and Pigments, and of Their Powers in Painting, &c
    Author: George Field
    Publisher: BiblioBazaar (2009)
    Binding: Paperback, 306 pages