MODULE: Colour perception
Step 06 of 09: Subjectivity in colour
People are able to adjust to varying amounts of light and still recognise familiar items because it creates less burden on our visual systems than having to interpret colours as completely unique experiences every minute of every day. We even adjust our susceptibility to colour on a daily basis, in a process know as PURKINJE's effects (1825), when the sun sets and the white light of day that suited our conical photoreceptors well gives way to darkness and we employ greater use of the rods instead and we become sensitive to bluer shades. One explanation for this is an evolutionary hypothesis suggesting that objects which are familiar do not require re-learning under diminishing light conditions, so a mother's face is still endearing despite new lighting conditions and a lion is still dangerous even though it may seem more grey than we expect it to be. This is called Colour constancy, also known as Chromatic Adaptation. In a practical setting, Photographers regularly have to adapt the white-balance setting on their cameras to counter the impact of the lighting conditions (fluorescent and incandescent lighting omits different coloured light), which is often improperly oversimplified as being the "colour temperature" of a scene. Here is another example from Professor KITAOKA, it shows grey rings within a blue-green composition, we perceive the grey rings as being pink/red because our eyes are compensating for the blue "atmospheric lighting" of the scene. Because our visual cortex assesses the scene as being a predominantly blue setting, it "subtracts" blue from the overall picture, resulting in the opposite colour to blue: red. This is mainly in the neutral areas (grey) as they are easiest to impose colour upon, not omitting any themselves;
