Page:A color notation (Munsell).djvu/103

 forations are arranged in several rows, each row giving different spaces between the perforations. In the case of the girl’s cloth- ing, the same sequence produces quite a different effect, if two perforations of the over-mask are brought nearer to select a lighter yellow-green dress, while the ends of the sequence remain unchanged. To move the middle perforation near the other end, selects a darker bluish green dress, on which the trimming will be less contrasted, while the hat appears brighter than before, because of greater contrast.

(170) The variations of color sequence which can thus be studied out by simple masks are almost endless; yet upon a measured system the character of each effect is easily described, and, if need be, preserved by a written record.

(171) Experiments with variable masks for the selection of color intervals, such as have been described, soon stimulate the imagination, so that it conceives sequences through any part of the color solid. The color image becomes a permanent mental adjunct. Five middle colors, tempered with white and black, permit us to devise the greatest variety of sequences, some light, others dark, some combining small difference of chroma with large difference of hue, others uniting large intervals of chroma with small intervals of hue, and so on through a well-nigh inexhaustible series.

(172) As this constructive imagination gains power, the solid and its charts may be laid aside. We can now think color consecutively. Each color suggests its place in the system, and may be taken as a point of departure for the invention of groups to carry out a desired relation.

(173) This selective mental process is helped by the score de-