COLOR IN CARTOGRAPHY Four color characteristics important in thematic mapping, meaning the psychological and aesthetic aspects of printed (NOT digital)

COLOR IN CARTOGRAPHY

Four color characteristics important in thematic mapping, meaning the psychological and aesthetic aspects of printed (NOT digital) color.

Color Perception

Sensing and cognitive processing of color

Color Specification Systems

The exact naming of colors

Design Strategies

Use color to its fullest potential in map communication

Cartographic Conventions

Qualitative and Quantitative conventions

COLOR IN CARTOGRAPHYCOLOR PERCEPTION

Color Perception -----

Is more difficult

► In low light (limits perception to achromatic)

► On tiny objects (< .06 inch at distance of 12 inches)

► For people who are color blind

Is affected by

► Light sources (solar, flourescent, tungsten bulb)

► Object surface (media)


HUE

Name of the color we perceive – red, green, blue, etc.

Most color wheels have 8 – 12 hues, no more than 24

The most complex maps (soils, geology) generally have ≤ 12 hues


VALUE

Lightness or darkness of color

Also called tint, shade, tone

Created by adding white or black to a hue

≤ 5 values of a color are the most that can be easily

distinguished on a map

Discrimination depends on background color – dark vs.

light


CHROMA

Saturation, intensity or purity of the color

Varies by adding pigment to gray

Chroma varies from 0% (neutral gray) to 100% - pure

(maximum color, no gray)

Hue affects chroma level – intense yellow appears

brighter than intense blue-green


Perception of a color is modified by its environment:

• Simultaneous contrast – adjacent colors appear lighter

in the direction of the darker color, and darker in the

direction of the lighter color

• Successive contrast – same color may appear lighter

against a dark background, and darker against a light

background


Warm colors: longer wavelengths – red, orange, yellow

Cool colors: shorter wavelengths – violet, blue, green

Children prefer warm colors, adults prefer cool colors

North American adults prefer these colors, in this order: Blue, Red, Green, Violet, Orange, Yellow

Greenish-yellow hues are unanimously disliked


For Children’s Maps:

Stay in the basic spectrum – blue, green, yellow, orange, red

Avoid dull, unattractive colors – stay with spectral hues

Children reject the gray scale – avoid achromatic schemes

Color saturation should be slightly less than 100%

Stick with the expected – water is blue


Colors in Combination:

Best combinations result from large difference in lightness (value) between figure and ground

Background color must be either light or dark

Pleasant figure hues are in blue-green range, or those with little gray

Unpleasant hues are yellow to yellowish-green, or those with considerable gray

Vivid colors combined with grayish colors form a pleasant combination


Advancing and Retreating colors:

o Advancing colors appear ‘closer’ to the viewer than retreating colors

o Advancing colors should be used for figure – retreating colors used for ground

o Advancing colors = warm hues, high values, deep saturation (deep, dark reds)

o Retreating colors = cool hues, low values, less saturation (grayish, light blues)

COLOR IN CARTOGRAPHYDESIGN STRATEGIES

The Function of Color in Design:

• Simplifying and Clarifying Agent – differentiate figure

vs. ground or unify various map elements

• Contributes to General Perceptibility – lends legibility,

visual acuity, clarity of differences

• Elicit Subjective Reactions – people respond to color


Developing Figure and Ground Relationships:

Perceptual grouping of colors is a strong tendency –

similar hues or brightness, warm or cool colors, etc.

Since warm color ‘advance’ they take on figural

qualities better than cool colors, which make good

ground colors

Color combination affects figure and ground

development


Figure Color Ground ColorYellow BlackWhite BlueBlack OrangeBlack YellowOrange BlackBlack WhiteWhite RedRed YellowGreen WhiteOrange WhiteRed Green

Best

W

orst


Color Provides Contrast:

Contrast is the most important design element in thematic mapping

Contrasting Hue clarity, legibility, visual hierarchy

Contrasting Value/Saturation visual interest, quantitative information, high values emerge as figure

Render ‘far away’ objects in cool tones, close objects in warm tones

Legibility of lettering on maps is greatly affected by both text and background colors

COLOR IN CARTOGRAPHYCOLOR CONVENTIONS

Qualitative Color Conventions (kind/quality):

Stick with hue variations only

Blue – water, cool temperatures

Red – warm temperatures

Yellow/Tan – arid and sparsely vegetated

Brown – land surface

Green – thick and lush vegetation


Quantitative Conventions (amount):

Color Plan by David Cuff –

Use gray and simple hues only

Part-spectral – use two colors adjacent on color wheel, plus intermediate hues

Full-spectral – use a separate hue for each different amount (red – highest)

Double-ended – illustrate positive to negative values by going from one dark hue, through light values, to a second dark hue (i.e. red – blue)


Quantitative Conventions (amount):

Color Plan by Janet Mersey –

Series of individual hues

Double-ended (same as Cuff)

Spectral – includes differences in value and intensity

Hue-value – light value of one hue to a dark value of a second hue

PMS value – different values of one hue

Gray scale – no hues used

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COLOR IN CARTOGRAPHY Four color characteristics important in thematic mapping, meaning the psychological and aesthetic aspects of printed (NOT digital)