Colour

• Transparent - all light transmitted
• Translucent - some light transmitted
• Opaque - no light transmitted
• Dispersion - a prism splits a ray of white light into a spectrum of colours
• When white light is split, the colours always follow the same order
• Red light is refracted the least as it has the longest wavelength
• Violet light is refracted most as it has the shortest wavelength
• Red - least refraction, longest wavelength

  Orange

  Yellow

  Green

  Blue

  Indigo

  Violet - most refraction, shortest wavelength
• Primary colours:

  • green, red and blue
• What colours mix to form secondary colours:

  • red and green = yellow
  • green and blue = cyan
  • blue and red = magenta
• White light can be made by mixing green, red and blue
• How do filters work:

  • filters absorb all colours except for its own colour, which is transmitted