• Yellow

• Wavelength: 570-590 nm
• Emotion: surprise
• the brightest color in the visible spectrum by luminance
• evolutionary signal: sudden light, dawn, alerting patterns, attention grab

• properties

  • highest luminance — the first color the eye detects
  • triggers orienting response: turn, look, assess
  • the color of gold, sulfur, sunlight, pollen

• in nature

  • warning patterns: wasps, bees, poison dart frogs — yellow-and-black means danger
  • flowers: pollinator attractant, advertising nectar
  • dawn and dusk: the transitional light, the moment of change
  • lightning: sudden discharge, raw energy

• in prism

  • attention needed, new event, unexpected state change, notification
  • the alert signal — something just happened, orient yourself