Color Use Guidelines for Data Representation

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Color Use Guidelines for Data Representation

• Civil Engineering Ping-Hung Lin

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Introduction

• Color and other graphic parameters necessary in
  cartography because we lose location to
  geographic location
• A map is a multivariate graph with latitude and
  longitude already claiming the x and y axes

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Hue and Color Mixing

• Hue is the perceptual dimension of color that we
  associate with color names, like red, green,
  blue, and yellow

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Lightness and Saturation

• Other two perceptual dimensions
• Another word for lightness is value.
• Saturation is vividness of a color

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Types of Color Schemes

• Sequential Schemes
• Qualitative and Binary Schemes
• Diverging Schemes
• Two-Variable Schemes
• Additional Issues

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Sequential Color Schemes

• Most basic guidance is to use lightness to
  represent ordered data
• Darker colors used to represent higher data
  values - light-to-dark for low-to-high

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Sequential Color Schemes
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Sequential Color Schemes
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Qualitative and Binary Schemes

• Categorical differences in data are usually
  represented with differences in hue
• Pay attention to the lightness and saturation of
  the hues you choose for a qualitative scheme

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Qualitative Schemes
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Binary Schemes
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Diverging Schemes

• Visual comparisons can be done with multiple
  graphics or mapping differences to a single
  graphic
• Careful use of hue and lightness determine
  success

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Diverging Schemes
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Diverging Schemes
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Two-Variable Schemes

• Six useful combinations of the one-variable
  schemes
• sequential-sequential , qualitative
• binary-qualitative , diverging
• Sequential , diverging-diverging

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Sequential-sequential
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Sequential-diverging
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Color Brewer
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Additional Issues

• Ignoring saturation can create confusion
• Doesnt recommend using saturation as primary
  symbolization for data set

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Problems in Color Appearance

• Colorblind can still see lightness differences
  and fairly wide range of hue differences.

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Problems in Color Appearance

• Small colored objects will be more difficult to
  identify than larger colored areas
• Different surroundings also change the appearance
  of a color

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Color Preference

• Do not concern which colors audience will like
• People like graphics with many color

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Thank you for your attention

• References
• C. A. Brewer, Color Use Guidelines for Data
  Representation,