If my friends and I disagree about a colour (is it blue or green? Red or orange?) how can we find out which it is if we

Question: If my friends and I disagree about a colour (is it blue or green? Red or orange?) how can we find out which it is if we all see colours differently?
- Keywords:
  argument,
  colour,
  light
Asked by josephineo to Ben, Dave, Susana on 27 Jun 2013.
- David Briggs answered on 27 Jun 2013:
  
  Take a picture with a digital camera, load the picture into photoshop or something like that, use the ‘pick colour’ command and find out what colour it is from the palette in photoshop. That should do it!
- Benjamin Hall answered on 27 Jun 2013:
  
  Yes.
  
  Machines can tell you. But then what if the person who programmed the machine saw colours incorrectly?!

Question: If my friends and I disagree about a colour (is it blue or green? Red or orange?) how can we find out which it is if we all see colours differently?