|sRGBB (r, g, b)||(0, 71, 171)|
|HSV (h, s, v)||(215°, 100%, 67%)|
|CIELChuv (L, C, h)||(33, 82, 259°)|
|ISCC–NBS descriptor||Vivid blue|
|B: Normalized to [0–255] (byte)|
3D model (JSmol)
|Molar mass||176.892 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Cobalt blue is a blue pigment made by sintering cobalt(II) oxide with aluminum(III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl2O4. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue. It is extremely stable and historically has been used as a coloring agent in ceramics (especially Chinese porcelain), jewelry, and paint. Transparent glasses are tinted with the silica-based cobalt pigment "smalt".
Cobalt blue in impure forms had long been used in Chinese porcelain. The first recorded use of cobalt blue as a color name in English was in 1777. It was independently discovered as a pure alumina-based pigment by Louis Jacques Thénard in 1802. Commercial production began in France in 1807. The leading world manufacturer of cobalt blue in the nineteenth century was Benjamin Wegner's Norwegian company Blaafarveværket ("blue colour works" in Dano-Norwegian). Germany also was famous for production of it, especially the blue colour works (Blaufarbenwerke) in the Ore Mountains of Saxony.
Cobalt glass is used decoratively, and also as an optical filter to remove or hide certain visible colors.
An example of cobalt blue hue (not pure cobalt blue)
Pierre-Auguste Renoir, Boating on the Seine (La Yole), c. 1879
Cobalt blue is toxic when ingested or inhaled. Its use requires appropriate precautions to avoid internal contamination and to prevent cobalt poisoning.
A single record of the compound concerns inclusions in sapphires from a single site.
Well, he's blue because that's Sega's more-or-less official company color