Any graphical image, including printed and electronic pages,
and computer software displays and GUIs (graphical user interfaces)
. . .
(none)
When color is used arbitrarily and gratuitously information is
obscured.
Favorite Colors
Many people make the mistake of choosing colors simply because
because they like them.
If you use colors simply because they happen to be your
favorites they will be irrelevant to what you want to
say,
and they almost certainly won't be other people's favorites.
For online documents people like to set up the graphical
interface preferences with their
own favorite colors.
Hence, if there is no functional reason to use particular colors,
the choice should be left to the user.
Being Color Happy
Another common mistake is being seduced by the availability of
a rich color palette.
The first instinct of a child presented with a big box of crayons
is to try them all.
This same phenomenon can be observed when people are presented
with new media.
When color monitors became affordable for the consumer PC market,
some software engineers tended to become "color happy", and the
same phenonmenon can be observed in many Web sites today.
The availability of so many new colors, enabled by new technology,
seduces people into overusing them.
Gratuitous use of color is dysfunctional.
Too many colors can obscure whatever rationale might exist for
using different colors, obliterating their information
value.
A very colorful display may attract attention at first, but it
can actually hinder the readability or information structure of
what's on the screen.
In
The Visual Display of Quantitative Information
Edward Tufte cites examples of "graphic puzzles" where data is color
coded, but the code is so complex the viewer cannot
make visual sense of the graphic.
If you can't think of a reason for something to be a different
color, it probably shouldn't be a different color.
The Function of Color
Properly used, color itself can convey information.
It can reinforce typographic information,
add to order and logic, indicate varying qualities and quanities,
call attention and emphasize, establish tone or connotation,
and clarify complex ideas.
Generally speaking, use "neutral" colors like black, white, and greys
to just present the facts with no particular "spin", and use other
colors sparingly to reinforce or enhance a message.
Be careful with simplistic cliched color associations like "yellow
means caution" and "red means danger", however. As discussed in
Colors In Context,
colors change depending upon both physical and psychological
situations.
Another function of color as information is purely physiological.
For example, a rule of thumb for legible typography is to
maintain high contrast between the background and the type.
However, because of the intense brightness of some computer monitors
a pure white background may cause eye fatigue, so a
slightly pastel or grey background may be better.
(This is the rationale behind the amber monitors briefly
popular in the 1980s.)
