est
vague analogies that fail when put to the test. Color needs a new set of
expressive terms, appropriate to its qualities, before we can make an
analysis as to the harmony or discord of our color sensations.

(47) This need is supplied in the present system by measured CHARTS, and
a NOTATION. Their very construction preserves the _balance of colors_,
as will be shown in the next chapter, while the chapter on harmony
(Chapter VII.) shows how harmonious pairs and triads of color may be
found by MASKS with measured intervals. In fact, practice in the use of
the charts supplies the imagination with scales and sequences of color
quite as definite and quite as easily written as those sound intervals
by which the musician conveys to others his sense of harmony. And,
although in neither art can training alone make the artist, yet a
technical grasp of these formal scales gives acquaintance with the full
range of the instrument, and is indispensable to artistic expression.
From these color scales each individual is free to choose combinations
in accord with his feeling for color harmony.

Let us make an outline of the course of color study traced in the
preceding pages.[15]

[Footnote 15: _See_ Part II., A Color System and Course of
Study.]

+PERCEPTION of color.+

(48) _Hue-difference._

Middle hues (5 principals).
Middle hues (5 intermediates).
Middle hues (10 placed in sequence as SCALE of HUE).

_Value-difference._

Light, middle, and dark values (without change of hue).
Light, middle, and dark values (traced with 5 principal hues).
10 values traced with each hue. SCALE of VALUE. _The Color Sphere_.

_Chroma-difference._

Strong, middle, and weak chroma (without change of hue).
Strong, middle and weak chroma (traced with three values without
change of hue).
Strong, middle, and weak chroma (traced with three values and
ten hues).
Maxima of color and their gradation to white, black, and gray.
_The Color Tree._

+EXPRESSION of color.+

(49) _Matching and imitation_ of hues (using stuffs, crayons, and
paints).

_Matching and imitation_ of values and hues (using stuffs, crayons,
and paints).

_Matching and imitation_ of chromas, values, and hues (using stuffs,
crayons, and paints).

_Notation of color._

Value V
Hue ------ , H - ,
Chroma C

Initial for hue, numeral above for