Steel blue
- HEX
- #4682B4
- RGB
- 70 130 180
- HSL
- 207° 44% 49%
- CMYK
- 61 28 0 29
Steel blue or Azure?
Greyer and calmer than azure.
Science
Real blued steel isn't painted. Heat polished steel to about 300 °C and an oxide film a few dozen nanometers thick grows on it. Light bouncing off the top and the bottom of that film interferes, and the steel shows blue. Watchmakers still blue screws and hands this way.
Kin
- Gunmetal: Another grey-blue named after worked metal
- Silver: Polished metal greys: silver tarnishes, steel blues when heated
- Petrol: Both named after industrial materials
In paintings
- Water Lilies, Claude Monet
Sources
- Bhadeshia, 'Oxide on steel and tempering colours', University of Cambridge
Hex values are screen approximations. Every page lists its sources.