What is light?
An electromagnetic wave; different wavelengths correspond to different colours.
What does monochromatic mean?
Light composed of a single wavelength.
What does heterochromatic mean?
Light composed of multiple wavelengths; perceived colour corresponds to dominant wavelength.
What is hue?
The aspect of colour we refer to as ‘colour’ itself (e.g., red, blue).
What is saturation?
The purity or vividness of a hue.
What is the CIE colour space?
A coordinate system (x,y) defined by the Commission Internationale de l’Eclairage to represent all perceivable colours.
What is achromatic light?
Light without a dominant wavelength; appears colourless (white, gray, or black).
What does colour as a construct mean?
Colour is a perceptual experience; light waves themselves are not coloured.
What is additive colour mixing?
Mixing primary lights (red, green, blue) to create other colours; used in digital displays.
What is subtractive colour mixing?
Mixing pigments or inks (cyan, magenta, yellow) that absorb wavelengths and reflect the rest.
What are non-spectral purples?
Colours not found in the spectrum; created by combining multiple wavelengths.
What are metamers?
Physically different stimuli perceived as identical in colour.
Why do humans have three primary colours?
To match any visible wavelength using combinations of three cone types.
What is trichromacy?
Colour vision based on three cone types (S, M, L).
How many cone types do most mammals have?
Two (dichromats).
How many cone types do some birds have?
Four (tetrachromats).
How many cone types does the mantis shrimp have?
Sixteen (hexadecachromat).
What is the trade-off between detail and colour?
Better colour discrimination often reduces fine spatial acuity.
What is total colour blindness?
Having only one type of cone or only rods; results in no colour discrimination.
What happens if only one type of cone is present?
Good spatial acuity, no colour discrimination.
What happens if only rods are present?
Poor spatial acuity and no colour discrimination.
What is protanopia?
Missing L-cone (red).
What is deuteranopia?
Missing M-cone (green).
What is tritanopia?
Missing S-cone (blue).
