Geography Reference
In-Depth Information
were introduced to support distinguishability and the association of the colors with
the annoyance levels. An experiment, including the developed scheme, proved the
hypothesis that class and color distances should be matched (cf. guideline 2)
(Weninger
2013
). Especially Brewer schemes in orange, green, blue, and red, that
appear approximately uniform, lead to an underestimation of the sound pressure
level, in contrast to schemes with hue-steps. Consequently, we recommend the use
of schemes with hue-steps. Moreover, further discussions of the results showed
light colors, representing low noise levels, were too saturated and, therefore, too
salient. In the third design [Fig.
1
(2a, b) and (4)] a special focus was put on the
gradation of saturation. To achieve that areas representing high values are more
salient they have to be more saturated than the other colors. The adjustment of
saturation was achieved by re-designing the scheme in the Munsell color space,
which defines colors by the parameters hue, saturation and lightness (Munsell
1905
). This way an increase of saturation and a decrease of lightness for higher
values can be facilitated which results in a systematic color order and thus hierar-
chy. It also helps to induce a three-dimensional effect to highlight hotspots. The five
hues—blue-green, yellow, orange, red, purple—are used, which results in a max-
imum of three lightness steps per hue. The hue-steps in combination with high
contrasts are meant to represent a big data range to indicate the logarithmic scale.
They also enhance differentiation and thus counteract effects of simultaneous
contrast. Each hue stands for a certain level of noise nuisance to support recognition
of levels. In the style of a traffic light scheme, which is seen clearly to communicate
the exceedance of a value, a diverging scale was implied, using light yellow as a
neutral point between moderate nuisance and higher levels of nuisance. By means
of the diverging scheme the positive and negative extreme values are highlighted. A
bluish green was used to help people with CVD to discriminate green and red.
Conclusion and Outlook
We gave an overview of the manifold perceptional and psychological effects
on colordesign, such as color contrast, effect of depth, effects on the per-
ceived object size, the emotional and associative aspects of color, and (situ-
ational) color vision deficiencies. While in recent cartographic work often the
technical aspect of color design, for example, automatically generating pal-
ettes are the focus (Steinr¨cken and Pl¨mer
2013
) we emphasized percep-
tional issues in the development of guidelines and decision criteria that
especially consider digital maps. In particular different kinds of color con-
trasts and the emotional aspect have been covered in more detailed.
Our hypothesis is that a big variety of output devices and manifold patterns
of use, which are characterized by different lightning conditions, screen sizes
and visual angles, effect color perception and thus color design. One of the
major aspects here is the consideration of color vision deficiencies, both
inherent and situational, in the design of a color scheme.
(continued)
