1. The Colour of Objects:
Subtractive colour theory

2. Transmission, Reflection, and Absorption
Light transmission is the process by which light travels through a medium
A transparent medium is a material that lets light pass through it
Examples: glass, air, pure water, plastic wrap

3. Transmission, Reflection, and Absorption
Absorption is the taking in of light by an object
An opaque medium is a material that does not let light pass through it
Examples: wood, stone, brick

4. Transmission, Reflection, and Absorption
Reflection is when light bounces off of the surface of an object
Most opaque objects absorb some light and reflect some light
A translucent material transmits some of the light that hits hit, and absorbs or reflects the rest. They are partially see- through
Examples: frosted glass, wax paper

6. Colours of Objects
Pigments are chemicals that absorb some colours of light and reflect other colours
Any opaque object that is coloured contains pigments
The colours of light that are reflected by the pigment are what our eyes see

7. Subtractive Colour Theory
The subtractive colour theory states that the apparent colour of a non-luminous object depends on which colours of light it absorbs and which it reflects
Diagram - blue object absorbs red and green and reflects blue

8. Primary Colours of Pigment
The primary colours of pigment are magenta, cyan, and yellow
They are the same as the secondary colours of light
Any colour of pigment can be produced by mixing different combinations of these colours
yellow
cyan
magenta

9. Secondary Colours of Pigment
The secondary colours of pigment are red, green, and blue
They are the same as the primary colours of light
Formed by mixing pairs of primary colours of pigment
red
green
blue

10. Black?
To make black, all three primary colours of pigment are mixed together
This will absorb all three primary colours of light, so no light will be reflected, and the pigment will appear black

12. Colours of Objects in Coloured Light
Diagrams

13. Colour of Transparent Objects
A coloured filter is a transparent object that is a certain colour
When light strikes a blue coloured filter, red and green light are absorbed and blue light is transmitted
Diagrams