Color Theory
Which colours is white light made of?
Did you know?! Your eyes have only 3 types of cells that can recognize millions of colours.! When you observe a colour, it is because different combinations of these cells are stimulated.! A TV screen uses a system of only three colours to create the effect of many different colours, just like the cells in your eyes.
Color Mixing Color can be perceived either from 1) a luminous object (TV, monitor, projector) using the Additive Approach 2) reflected pigment or ink (printouts, materials) using the Subtractive Approach
Additive Color Model
Additive Color Model! Used by luminous objects ex. Computers, TV, projectors
Additive Color Model! Used by luminous objects ex. Computers, TV, projectors! When light energy is added, a color appears brighter
Additive Color Model! Used by luminous objects ex. Computers, TV, projectors! When light energy is added, a color appears brighter
Additive Color Model! Used by luminous objects ex. Computers, TV, projectors! When light energy is added, a color appears brighter! The additive primary colours are (RGB):
Additive Color Model! Used by luminous objects ex. Computers, TV, projectors! When light energy is added, a color appears brighter! The additive primary colours are (RGB): Red Green Blue
Additive Color Model! Used by luminous objects ex. Computers, TV, projectors! When light energy is added, a color appears brighter! The additive primary colours are (RGB): Red Green Blue
! Different percentages of red, green, & blue light are used to generate different colours
! Different percentages of red, green, & blue light are used to generate different colours
! Different percentages of red, green, & blue light are used to generate different colours
! Different percentages of red, green, & blue light are used to generate different colours
! Different percentages of red, green, & blue light are used to generate different colours! White light is created when Red, Blue and Green are mixed together
! Different percentages of red, green, & blue light are used to generate different colours! White light is created when Red, Blue and Green are mixed together
! Different percentages of red, green, & blue light are used to generate different colours! White light is created when Red, Blue and Green are mixed together
! Different percentages of red, green, & blue light are used to generate different colours! White light is created when Red, Blue and Green are mixed together
! Different percentages of red, green, & blue light are used to generate different colours! White light is created when Red, Blue and Green are mixed together
! http://dev.physicslab.org/asp/ applets/additivecolors/ default.asp
Our Eyes
Our Eyes
Our eyes use the additive colour approach, but how do we see colour if all wavelengths are coming in from the sun (white light)?
Objects absorb all colors except the color being seen, which is reflected White light Green Light reflected White light White Light reflected Green Surface White light Blue Light reflected White Surface White light Red Light reflected White light Blue Surface No Light reflected Red Surface Black Surface
! Objects absorb all colors except the color being seen, which is reflected " White surface = all wavelengths (blue, red, green) are being reflected " Black surface = all wavelengths are being absorbed. " Red surface = blue and green wavelengths are absorbed, red is reflected " Green surface = blue and red wavelengths are absorbed, green is reflected.
! Questions, why are clouds white?
! Questions, why are clouds white?
! Questions, why are clouds white?! Why is it not a good idea to wear black in the summer?
Subtractive Color Model
Subtractive Color Model! Used in the print media ex. inks, fabrics, paints, crayons, etc.
Subtractive Color Model! Used in the print media ex. inks, fabrics, paints, crayons, etc.! When more color is added, a color appears darker
Subtractive Color Model! Used in the print media ex. inks, fabrics, paints, crayons, etc.! When more color is added, a color appears darker! The subtractive primary colours are (CMY): Cyan
Subtractive Color Model! Used in the print media ex. inks, fabrics, paints, crayons, etc.! When more color is added, a color appears darker! The subtractive primary colours are (CMY): Cyan Magenta
Subtractive Color Model! Used in the print media ex. inks, fabrics, paints, crayons, etc.! When more color is added, a color appears darker! The subtractive primary colours are (CMY): Cyan Magenta Yellow
# Secondary colours produced by CMY colours are Red Green
# Secondary colours produced by CMY colours are Red Green Blue
# Secondary colours produced by CMY colours are Red Green Blue
# Secondary colours produced by CMY colours are Red Green Blue! Different percentages of cyan, magenta & yellow light are used to generate different colours
# Secondary colours produced by CMY colours are Red Green Blue! Different percentages of cyan, magenta & yellow light are used to generate different colours
# Secondary colours produced by CMY colours are Red Green Blue! Different percentages of cyan, magenta & yellow light are used to generate different colours! There is no way of making white by adding CMY colour sources, the paper/canvas must be white to start with.
Colour Blindness! 1 out of 10 men and 1 out of 200 women have some type of color deficiency.! The most common type is mistaking red and green.! The second most common type is mistaking blue and yellow