Colour Flashcards
(52 cards)
1
Q
Why is colour important?
A
- Clarifies
- Simplifies
- Attracts Attention
- Leads the Eye
- Enhances Perceptibility
2
Q
Color Brewer
A
- Website resource for colour choices
- Powerful cartography tool
- Created by past Cartography student
3
Q
What are key things to understand about colour?
A
- Visual reaction to colour
- Visual sensation of colour
- How colours interact with each other
4
Q
Figure Ground
A
- Ability to separate elements based upon contrast
- Employed to discern difference between back ground and foreground
- Not just about lines, but how it is shaded
- Famous example: Rubin’s Vase
5
Q
Rubin’s Vase
A
- Classic example of figure ground optical illusion
- Is it a vase, or two faces
- Shows how perception can play a role in cartography
6
Q
Is the flag of Canada an optical illusion?
A
- Not really but it could almost look like two people fighting
7
Q
How do we see colour?
A
- Receptors in the eye that are stimulated by portion of electromagnetic spectrum
- We distinguish 7 predominant colours (hues)
- ROYGBIV
8
Q
Electromagnetic spectrum
A
- Entire spectrum appears as white light
- When refracted through prism actually shows the various wavelengths as the 7 predominant colours ROYGBIV
- Humans see 400-700nm
9
Q
What portion of the electromagnetic spectrum do humans see?
A
- 400-700nm
- ROYGBIV
- Some people don’t see all and are colour blind
10
Q
How do lightbulbs affect colour?
A
- Light bulbs change colour
- Full spectrum lightbulbs are more comfortable because they produce natural light
11
Q
ROYGBIV acronym
A
Ring Out Your Great Bells In Victory
12
Q
What are the 3 dimensions of colour?
A
- Hue
- Chroma
- Value
13
Q
Hue
A
- Colours, ROYGBIV
- Infinite number of colours
14
Q
Chroma
A
- Intensity, not brightness
- Saturation, purity
- Compare colour to neutral grey, with addition of pigment, will appear less and less grey
- White, Grey, and black are achromatic
15
Q
Which colours are achromatic?
A
White, Grey, and black are achromatic
16
Q
Value
A
- Lightness or Brightness of hue
- Measured w/ instruments
- Conceptually easy, difficult in practice
- Subjective for humans, but can measure w/ spectral responses
- Computer usually manages value
17
Q
What are the 2 key ways of classifying colour?
A
- Additive Light Mixing
- Subtractive Pigment Mixing
18
Q
Additive Light Mixing
A
- RGB
- Colours added to produce new colours
- White is all colours, black is no colours
19
Q
What is Additive Light Mixing used for?
A
- For projecting
- RGB
20
Q
Subtractive Pigment Mixing
A
- CMYK
- K is black
21
Q
What is Subtractive Pigment Mixing used for?
A
- For printing
- CMYK
22
Q
What does CMYK stand for
A
Cyan, Magenta, Yellow, K is black
23
Q
What is the main difference between RGB and CMYK?
A
- Additive RGB is how computers display and project colour
- Subtractive CMYK is how printers will display colour
24
Q
Why does CMYK need the K?
A
Because CMY cannot mix together to create a good enough black on their own
25
What are examples of colour classification systems and years established?
- Munsell (1915)
- Ostwald (1917)
- CIE (1931)
- RGB
26
Explain the Munsell colour classification system
- 1915
- 10 major hues
- 10 value levels
- 12 chroma levels
- 1500 total colour specs
- Subtractive, Good for print not digital
- Used a physical 3D model to find colours
27
Describe the Munsell 3D model to find colours
- Wheel of 10 hues
- Vertical center representing 10 value levels
- Horizontal from wheel represents 12 chroma levels for each hue on the wheel
28
Explain the Ostwald colour classification system
- 1917
- 24 hues on hue circle
- Adds different amount of white/black on vertical
- Represented by C (colour), W (White), and B (Black)
- Simple, precise
- Subtractive pigments
29
What does 40, 10, 50 represent in the Ostwald colour system?
40% colour, 10% White, 50% Black
30
Who was Ostwald and how did he develop his colour system?
- Physicist and Nobel Prize winner
| - Reflectance Curves
31
Explain the CIE colour classification system
- Additive digital system
- Reaction of light/energy hitting things
- Standard illumination source (tungsten lamp, noon sunlight, average sunlight on overcast day)
- Standard observer (average human response)
- Standard primaries (Red, green, blue)
32
What does CIE stand for?
Commission International De L'Eclairage
33
What are the standard primaries in the CIE?
- Red, x
- Green, y
- Blue, z
- Set up on a cube
34
Explain the RGB colour classification system
- 16 million possible colours
- Additive, digital
- RGB is XYZ with values between 0-255 each (256 #'s)
35
What does 0,0,0 represent in RGB?
Black
36
What does 255,255,255 represent in RGB?
White
37
What does 255,0,0 represent in RGB?
Red
38
What does 255,0,255 represent in RGB?
Magenta
| - all red, all blue
39
What are some considerations to take into account when choosing colours and colour combinations?
- Cultural Controls
- Convention
- Depth Perception
- Value
- Data Levels
40
What are the perceptual primaries and what are the other colours?
Primaries: blue, red, green, yellow, brown, black, white
| - Other colours appear as mixtures (pink, orange, etc.)
41
What does red represent culturally?
- Danger, Stop
42
What does yellow represent culturally?
- Sacred in East
| - Indecision in West
43
What are colours associated with funerals?
- White in India
| - Black in West
44
What colours are best for different age groups?
- High saturation chroma for children
| - Softer tones for older people
45
What is an example of a cultural colour that might be best to avoid?
- Blue = boys
| - Pink = girls
46
What are some cartographic conventions for colour?
- Blue = Water/cool
- Red = Warmth/ towns/ danger- Green = Vegetation/ lowlands/ forests
- Yellow = Dryness/lack of veg
- Brown = Contours/ landforms
47
What do blue and red represent on a geology map (cartographic conventions)
```
Blue = Carbonate (water formed, cool)
Red = Igneous (volcanic, hot)
```
48
How does depth perception affect colour (relates to physics)?
- Light rays refract inversely to wavelength
- Blue focus in front of retina and red focus behind retina
- Therefore red appears nearer than blue in front of the eye fractionally
- Red appears more important
49
What is value?
- Lightness or darkness
- Humans are not very sensitive to value
- Value appears inconsistent depending on interference by surrounding colours
- Can interfere with depth perception
50
What is one way to help choose colour schemes and help with figure ground?
- Use a colour wheel organized in chromatic order
| - Choose complimentary colour opposite on the wheel
51
Data levels with colour
- Nominal: colour has no meaning
| - Ordinal/ Interval/ Ratio: colour has meaning
52
What are some key guidelines for choosing colours on maps?
- Avoid too many colours
- Avoid loud colours
- Avoid clashing colours
- Keep It Simple (KIS)
- Design map for audience, not yourself
