Colour Theory (part 1) Lecture

• Colour is infinite and dependent on whats around it (effects how we see colour)

• Spectral colour is a single wavelength in the visible spectrum (we see some wavelengths as the same - same colour)

• All light is made up of all the colours vibrating at different wavelengths

• We see colour when white light reflects off a surface (separates into colours)

• A white surface reflects lights (takes on colour of light). A black surface absorbs light (doesn’t take on colour properties of light - remains black) - blue paper plus red light = purple

• The sky has no colour- perceive it as blue because of the reflection of white light off all the particle

• At the back of the retina in the eye = rods - pick up black and white info / cones pick up colour (different types pick up different colours)

• A combination of red orange and green wavelengths of light make us see yellow. Does yellow actually exist?

• The only colours that we actually see are red green and blue - others are combinations

• How do you know that what you perceive as red is the same as what the person next to you sees as red? 

• Josef Albes and Johannes Itten - wrote theories about colour - studied principles (thought it was key to being a practitioner) - maybe checkout their books - Colour and Colour Studies

• Red, blue, yellow - primaries. mix two to make secondaries (i.e. red plus yellow = orange)

• Complementaries - chromatic opposites (i.e. blue and orange, green and red, yellow and purple)

• Mix complementaries (all three primaries) and you get a neutral (brown or grey depending on levels of each colour) - add white to this and you get a grey (optically cancelling out each others wavelengths)

• So basically colour of light is different from colour of media..

• Light colour mode - red, green, blue (RGB mode on a screen) - additive (white on a screen is made by mixing all primaries) 

• Media colour mode - cyan, magenta, yellow, black (CMYK in physical pigment) - subtractive

• The primaries for one colour mode provide the secondaries for another - based on the same optical principles

• Chromatic value (colour) = hue + tone = saturation

• Tonal value is based on a colour's luminance (how much light it reflects) - as you mix more pigments into it it reflects less light 

• Tint = how much white you add to something (not becoming brighter but you are adding more light to it)

• Saturation - how pure a colour is - change its tint or tone to make it less saturated 

Overall, today's colour theory lecture was not particularly helpful to me because it was all stuff that I have already learnt in my History of Art, Biology and Painting alevels. However, it did bring things together nicely. One thing that I didn't already know was how the colours mixed in CMYK mode. This is something that I have always wondered.