I
The fundamental scientific method for measuring or specifying a
particular color was established in 1931 by the Commission Internationale
de l'Eclairage (CIE).[12] In this
system, the proportions of red, green, and blue light required to match a
given color are measured with a colorimeter, and the chromaticity
coordinates of the color are thus established. The Commission also
defined the characteristics of the standard observer and the
properties of three standard illuminants. The usual notation
of
a color consists of two of the chromaticity coordinates plus the luminance
value as established by spectrophotometer; these tristimulus
values represent dominant wave length, purity, and reflectance. For
example, the color of a tomato might be expressed as follows:
x
= .622; y = .350; Y = 10.2%.[13] However basic this
system is for scientific measurement, its disadvantages for bibliographical
description are obvious. To demand that bibliographers acquire the
necessary knowledge of optics would decimate their already small ranks;
and the prospect of setting up shop, with delicate and expensive
instruments, in each rare book room would eliminate the few that remained
— if, indeed, the librarians had not already resigned. Not only is this
method impractical for bibliographical purposes; it is undesirable. For the
degree of accuracy attainable with a spectrophotometer is not required in
a bibliographical description (and is thus wasteful of effort); in addition, it
could often be actually misleading, since it would continually reveal
variants, most of which (depending on the tolerances established by the
manufacturer of the cloth or the dye) would have no significance to the
bibliographer. To put the matter another way, if the bibliographer makes
finer distinctions than those required by the
adopted tolerances of the manufacturer, he may find himself recording as
variants bindings which came from the same bolt of material or consecutive
ones.
[14] Furthermore, the notation in
tristimulus terms is not one which could be readily comprehended by the
readers of a descriptive bibliography.
If the CIE system is not feasible for bibliographical work, the next
question to ask is whether or not another more appropriate system exists
which is at the same time scientifically accurate and respectable. The
alternative to spectrophotometric measurement is visual comparision with
material standards, such as a set of color chips (sometimes known as the
"ratio method"). Depending on the selection and production of the colors
represented in any given set of material standards,
this approach to color specification can be very precise and is scientifically
valid. Although individual perception of a color is subjective, the act of
matching a color with a carefully produced standard (which can then be
referred to by other persons) reduces to a minimum the effects of
subjectivity. And if the color chips have been chosen to represent particular
CIE specifications that will result in a systematic sampling of color space,
the whole process rests on a sound scientific foundation.
[15] Aside from the danger of fading,
an
unavoidable problem in any material standard, the principal limitation of
such systems is the necessity of interpolation. Since the eye can distinguish
about ten million colors and since there are theoretically an infinite number
of colors in three-dimensional color space, any color atlas or set of
standards must represent a selection based on some principle of organization
(hence the generic term "color-order systems");
therefore, depending on the number of colors selected and the accuracy of
specification required, it is sometimes necessary to estimate the relation of
a given color to two of the colors in the standard. This sort of interpolation,
though it can be performed skillfully with practice, remains of course a
subjective matter. A material color standard for bibliography should contain
enough colors that, within the limits of accuracy desired, interpolation
would seldom be required; on the other hand, it should not include so many
colors that the process of matching becomes time-consuming and
indecisive.
Color-order systems fall into three groups: (a) color-mixture (or
additive) systems contain copies of colors established by mixing colored
lights in particular proportions with a tristimulus colorimeter; (b)
colorant-mixture (or subtractive) systems contain colors produced by mixing
colorants (pigments, dyes) in various proportions; (c) color-appearance
systems contain colors arrived at by means of psychological
perceptions of color differences and spacing. Some systems, such as atlases
printed by a screen-plate process, are intermediate, partaking of the
characteristics of both the color- and colorant-mixture types.
[16] The methods by which the colors
are
produced, however, will be of less concern to the bibliographer than the
physical features and range of the resulting standards; and the three most
promising systems are surveyed here with the needs of the bibliographer in
mind:
(1) The Munsell System — In 1905 Albert H.
Munsell,
a Boston artist and teacher, published a little book called A Color
Notation, which he later supplemented with a Color
Atlas
(1915). This notation, with the system which lies behind it, is perhaps the
most widely used of the color-order systems. It is readily applicable to
diverse fields, and scientists often convert color information to Munsell
terms; it is the system described in the Encyclopaedia
Britannica's current article on "Colour" (by A. C. Hardy) and
officially recommended in 1942 by the American Standards Association,
and it is particularly useful for educational purposes.[17] The notation for any color contains
three
terms, since the eye detects three characteristics of color — hue,
brightness, and saturation (parallel to the CIE tristimulus values for
dominant wave length, reflectance, and purity); in the Munsell system these
qualities are referred to as
hue, value, and chroma. With
these
three "dimensions," a color solid, representing color space, can be
envisioned as an irregular sphere: the axis corresponds to the
value scale, from black at the south pole to white at the
north;
perpendicular distances from this axis indicate chroma, from
gray near the axis to the pure, fully saturated color at the surface of the
sphere; and planes perpendicular to the equator, passing through the axis,
represent hue.[18] Ten
hue
segments (made up of five basic hue names) are marked off around
the circumference of the equator plane: red, yellow-red, yellow,
green-yellow, green, blue-green, blue, purple-blue, purple, red-purple. The
axis is divided into ten steps from black to white, and the number of
possible chroma steps varies with the hue and value. Any color can then be
referred to in a form such as "R 4/8," in which R signifies "red," 4 means
the fourth step up from black toward white along the axis, and 8 indicates
the eighth step perpendicular to the axis on that value level. R 4/12 would
be more fully saturated and R 4/6 less; R 5/8 would be lighter and R 3/8
darker. Each hue segment may be subdivided into ten numbered planes so
that, for example, 7R 4/8 would be a yellower red than 5R 4/8, and 3R 4/8
would be more purple. This system of notation is flexible enough to
accommodate theoretically an infinite number of colors (by using decimals,
as in 3.7RP 8.4/3.3) but is simple enough to be immediately comprehended
(without reference to a table) by anyone
acquainted with it.
Another advantage is that the Munsell Color Company of Baltimore
publishes a wide variety of excellent color charts and atlases based on this
system,[19] and the continued
availability of the material is assured by the existence of a nonprofit
Munsell Color Foundation, established in 1942.[20] The basic publication is the
Munsell
Book of Color (1929-43, and later editions), issued in both a library
and a pocket edition; it is a loose-leaf book, each leaf representing a
constant hue plane, with small chips illustrating the possible chroma steps
on a number of value levels. The current (1960) pocket edition (7" x
4½") contains 1000 samples of a matte finish, each ⅝" x ½",
and costs $90; it is more suitable for bibliographical work than the library
edition, which is not so easily portable and contains glossy chips. However,
the chips of the library edition are removable, which is a great advantage;
and
even the matte chips of the pocket edition are not so satisfactory as cloth
samples would be for matching binding colors, and the price is another
hindrance to the widespread adoption of either edition for bibliographical
work. The same considerations would apply to the Opposite Hues Edition
of 1950 ($100) and the Neighboring Hues Edition of the same year ($155),
both with glossy chips. Of the many special Munsell charts
(Standards
for Plastic
Insulated Wire and Cable;
Plant Tissue Color
Charts;
Soil Color Charts;
Rock Color
Charts
for the Geological Society of America;
Value Scales for Judging
Reflectance), each representing a selection from the
Munsell
Book of Color, there is one which offers possibilities for
bibliographical description — the
Color Fan developed
by
Dorothy Nickerson for use in horticulture.
[21] Convenient in size (7¾" x
1⅞"),
each of the 40 hue leaves of the fan displays six or seven value steps, and
the samples (1⅞" x ⅞") fill the entire width of each leaf, avoiding
the usual disadvantage of nonremovable samples and greatly facilitating
comparison with a binding; there are 262 colors shown and the price is
$7.50. The limitation of the published
Fan is that it illustrates
only maximum chroma (other fans are planned to sample the sphere in
other ways), so that one would be dealing only with colors on the
surface of the sphere. All in all, the Munsell system has, from the
bibliographer's point of view, the advantages of continued availability, wide
acceptance and respect, an easily learned and comprehensive notation,
excellently produced charts, convenient size, and (in the case of the
Nickerson
Color Fan) a feasible price; its only real limitation
for the description of bindings is the discrepancy in surface texture between
the color chips and cloth.
(2) The Ostwald System — The other most
widely
known system is the one developed by Wilhelm Ostwald, 1909 Nobel
laureate in chemistry. His theories of color appeared in a long succession
of works following Die Farbenfibel (1916) and were
translated
by J. Scott Taylor in 1931 as Colour Science. The Ostwald
solid is a double cone with a vertical black-white axis; thus any hue plane,
up to the axis, may be pictured as an equilateral triangle, with its three
angles at the points of black, white, and the pure color. There are eight
steps from white to black, lettered a, c,
e, g, i, l,
n,
p; from each of these points lines are drawn parallel to the
other
two sides of the triangle and each intersection is labeled by the letters of the
two lines which meet there. Thus the points where the line from
e meets the other two sides of the triangle would be
ea and pe; and the point of saturation
would be pa. The equator of the double cone is divided into
twenty-four hue steps, each assigned a number; in this way a color can be
specified as 8pa or 10nc, and so on. The
system is
ingenious and has been widely used in solving problems of decoration and
color harmony, but two defects
are immediately apparent — one of theoretical, and the other of
practical,
importance. Because the point of highest saturation for any given hue falls
at the apex of a triangle which contains the other shades and tints of that
hue, no provision is made for the irregularities in the surface of the solid
resulting from the divergences in saturation attainable by different coloring
materials; so the system is inflexible, and the development of new methods
for producing greater saturation in a given hue necessitates readjusting the
entire triangle. On the practical level, the method of notation is much more
difficult to learn and remember than the Munsell notation.
Between 1932 and 1935 J. Scott Taylor arranged The Ostwald
Colour Album, which contained twelve plates in a box and displayed
about 1400 colors. But the most widely used collection of color chips based
on the Ostwald system is the Container Corporation of America's
Color Harmony Manual (1942; 2nd ed., 1946; 3rd ed., 1948)
by Egbert Jacobson, Walter C. Granville, and Carl E. Foss. The latest
edition contains 949 removable hexagonal chips (one side glossy and the
other matte) on loose leaf charts in a zippered portfolio. These features
make it extremely convenient, but its price of $150 militates against its
choice by bibliographers. In 1950 Helen D. Taylor, Lucille Knoche, and
Walter C. Granville published a Descriptive Color Names
Dictionary as a supplement to the third edition of the
Manual. The color names were selected after a survey of
previous dictionaries and of the terms used commercially by various
companies; by means of this dictionary the
Ostwald symbols may be translated into verbal expressions —
10pl is "deep eggplant" and 16ne is "peacock
blue."
However, such terms are somewhat too fanciful to give a clear idea of the
color to a reader of a descriptive bibliography who does not happen to have
the Manual at hand. In short, the Color Harmony
Manual is an admirably produced tool, but the Ostwald system on
which it is based is not so suitable a standard for bibliography as is the
Munsell system.
(3) British Colour Council Dictionary of Colour
Standards
— The color standard officially adopted by the British Standards
Institution (Standard 543-1934) is the Dictionary of Colour
Standards (1934; 2nd ed., 1951) issued by the British Colour
Council. The second edition displays 240 colors (twenty more than the first
edition), produced on silk ribbons, each divided into smooth and ribbed
surfaces and fastened as a loop so that the sample may be lifted enough to
insert the item to be matched beneath. The Dictionary takes
the
form of two volumes in a portfolio: one volume (57 pp.) is a list of the
colors, with their BCC numbers and the origin of the name; the other is a
folding chart exhibiting the colored ribbons, each sample numbered
consecutively
and assigned a name and a code reference. The fact that the
Dictionary is an officially adopted standard and the fact that
it
consists of cloth samples are enormous advantages, which no doubt lie
behind John Carter's choice of this
Dictionary for
bibliographical purposes, but its nomenclature is not so appropriate as might
be desired. In the first place, the identifying numbers (from BCC 1 to BCC
240), unlike the Munsell notation, give no indication of the position of the
color in color space. On top of that, the names, however conventional some
of them may be in certain fields, have often been chosen for industrial uses
and are not always clear to the general reader — for instance, BCC
71
is "Garter Blue," BCC 235 "Crayon Blue," BCC 239 "Gloucestershire
Green," BCC 142 "Corn Husk," and BCC 170 "Natal Brown." The colors
have usually been matched to the object named, as the description of the
origin of "Peacock Blue" (BCC 120) illustrates: "A very old colour name.
The
colour here given was matched to peacock feathers, and is a general
representation of samples submitted by textile and other colour using
industries." The arrangement of the samples is also less meaningful than
might be hoped: thus "Brick Red" (BCC 125) and "Guardsman Red" (BCC
126) are separated by several leaves from the related "Signal Red," "Post
Office Red," and "Union Jack Red" (BCC 208-210).
Of the other publications of the British Colour Council, two should
be mentioned. In 1938 the Council issued (in collaboration with the Royal
Horticultural Society) the first volume of a Horticultural Colour
Chart, also called the Wilson Colour Chart after
Robert
F. Wilson, the active and prominent general manager of the Council at that
time. It consists of a portfolio containing 100 loose plates of printed color
samples (not affixed chips). Each leaf lists foreign synonyms of the color
name and the equivalents in four other systems (BCC
Dictionary, Ridgway, Oberthür-Dauthenay, Ostwald);
it
also indicates a special notation for the color, in which the last two digits
stand for one of 64 hues and the preceding digit represents lighter tints
(600's and below) and darker shades (700's and above) — thus
"Rose
Bengal" is 25 and "Phlox Pink" is 625 — with prefixed zeros for
steps
of graying. In 1941 a second volume of 100 more plates was published.
These
two volumes, with their somewhat awkward notation and nomenclature and
their rather inconvenient physical form, would not be successful for
bibliographical description. The other publication is the one used by Stott
in his Maugham bibliography, the Dictionary of Colours for Interior
Decoration (1949), with 378 colors (labeled CC1-CC378) displayed
in silk samples in three volumes. The Council's regular Dictionary
of
Colour Standards contains cross references to this
chart, but the names do not always match — BCC47, "Victrix Blue,"
for
example, is the same as CC287, "Ming Blue." This situation does not seem
conducive to standardization of terminology, particularly when the terms are
not self-explanatory. Stott, after using this
Dictionary,
reported
that "many book cloths defy even the 378 examples shown on the chart" (p.
8); and a reviewer of his bibliography questioned the BCC nomenclature by
asking whether the gain in accuracy was "worth achieving at the cost of
superficial confusion in the minds of those who are more familiar with
The Library than with
Vogue."
[22] Another disadvantage of all three
publications was expressed by Cahill when asked why he adopted a paint
standard instead of the British Colour Council's
Dictionary:
"its
bulk and price make it an impossible tool for the Belloc collectors,
enthusiasts and booksellers for whom my book is mainly
intended."
[23]
The bibliographer should be aware of the features of certain other
systems, though none of them would serve as a practical choice for a
bibliographical standard: (1) the Standard Color Card of
America (9th ed., 1941), with 216 silk swatches, used mainly by the
textile industry, employs rather bizarre nomenclature and is an unsystematic
sampling of color space; (2) the DIN-Farbenkarte (1953),
with
samples representing equal psychological steps, is the official German
standard, not very widely known in England and America; (3) the great
Villalobos Colour Atlas (1947), probably the most extensive
guide available, shows 7279 samples, each with a hole in the center to
facilitate matching; (4) the Dictionary of Color (1930; 2nd
ed.,
1950) by Aloys J. Maerz and M. Rea Paul is the standard work on color
nomenclature, with 7056 colors on 56 plates, and it is no criticism of the
work's great authority to say that the small size of the color squares
(usually
144 to the page, with no holes for comparison) and the historical purpose
of the work (with some colors assigned no name at all) make it
inappropriate as a standard for bibliography; (5) the Plochere Color
System (1948) by Gladys and Gustave Plochere, with 1248 colors
on
3" x 5" cards (or smaller mounted rectangles), is basically a guide for
interior decorators; (6) Federal Standard No. 595 (1956),
with
358 color chips, is not a systematic sampling and is mainly intended for the
specification of paint colors in use by the United States government; (7)
Robert Ridgway's Color Standards and Color Nomenclature
(1912), with 1115 colors and names, was long a standard for naturalists but
is now out of print; (8) the Nu-Hue Color Coordinator (1949,
1952), prepared by Carl E. Foss for the Martin-Senour Company, is
perhaps the most ambitious and elaborately produced of the
colorant-mixture systems developed by paint manufacturers; (9) the 1962
Reinhold Color Atlas (in England the
Methuen
Handbook
of Colour), by A. Kornerup and J.H.Wanscher, displays 1266
colors
in extremely (perhaps overly) compact form. These systems are of course
only a few out of a possible list of seventy-five or more; but the
bibliographer cannot seriously consider the great majority of color charts,
devised specifically for stamp collectors, horticulturists, interior decorators,
paint dealers, textile dyers, or ornithologists.
Clearly the various attempts at color standardization have not in the
past led to any general system which encompasses or coordinates a large
number of them, and the bibliographer is faced with a multiplicity of
systems, none of which precisely suits his needs. The choice of one with
the fewest disadvantages becomes a matter of deciding which of the desired
features are most important — whether it is better to have a standard
with
a large number of colors, or a satisfactory nomenclature, or a low price, or
something else. There is no doubt that the problem of nomenclature is
extremely important for bibliographical description, because the reader of
a bibliography should not be required to consult a color chart except when
a question arises. He should not be confronted with "8pa" or "13432,"
unaccompanied by a commonly understood color expression; yet the
common expression must be firmly attached to a precise area in color space
so that it will hold the same meaning for each
user. Fortunately, such a system is now available.
