Graphics Programs Reference
In-Depth Information
Color contrast
Differences in color, called contrast, are the fundamental way we interpret the world.
Artists and vision scientists describe colors in terms of hue (red, blue, purple, etc.)
and lightness, plus a third dimension variously called saturation, chroma, or
“colorfulness.” Differences in hue create labels. Differences in lightness define
shape. Attention is drawn first to regions of high contrast.
The red roads contrast in both hue and lightness with the light-colored backgrounds.
The major highways are outlined in black, which makes the color look darker and
increases the contrast. The network of red highways creates the foremost visual
layer in this map, as this map is designed for drivers. The roads are labeled in
black, which optimizes contrast and readability.
The text that labels features in the light blue water is a slightly darker, more
saturated shade of blue. This creates a “blue” layer that is legible yet unobtrusive.
Similarly, Point Reyes is labeled in green to associate it with the green park region,
but more emphatically, as the destination for this map.
Get it right in black and white
The perceived lightness of a color is called
luminance or value
. Luminance can be
measured, captured by technology such as black and white cameras, or computed.
Reducing colors to their luminance values allows us to evaluate the contrast and
spatial relationships in a design without the distraction of hue.
