The Triad-Scales, whether in the Right Mode or in the Left Mode, are of great interest both in Pure Design and in Representation. In Representation, however, the number of tones between the limits of Black and White would, as a rule, be increased, as in the extended diagram given farther on.
150. Instead of taking the colors at a certain interval in one mode or the other, it is possible to take the colors in a certain relation of intervals repeated; this in either mode. The relation of a third to a fifth, for instance, being repeated, in one mode or the other, gives us some very interesting sequences. The one which follows is an example.
| LD-V, ⍁ 5th-3d | |||
| Wt | |||
| HLt | - | Y | |
| 3d | |||
| Lt | - | O | |
| 5th | |||
| LLt | - | V | |
| 3d | |||
| M | - | B | |
| 5th | |||
| HD | - | Y | |
| 3d | |||
| D | - | O | |
| 5th | |||
| LD | - | V | |
| Blk | |||
The relation of a seventh followed by two fifths, when repeated, in either mode, gives a large number of sequences of very great interest, particularly for Representation.
151. Any two of the sequences which I have described as those of the Vertical, or more than two, may be combined and used together. In that case we have two or more colors to a value. The monotony which is inevitable in any single vertical sequence is avoided in the combination of two or more such sequences.
| Seq. R and Seq. Y | ||
| Wt | ||
| R | HLt | Y |
| R | Lt | Y |
| R | LLt | Y |
| R | M | Y |
| R | HD | Y |
| R | D | Y |
| R | LD | Y |
| Blk | ||
This is an example of the combination of two vertical sequences—the sequence of Red and the sequence of Yellow. I have not found the sequences of this type very interesting. In using them in Representation I have found it desirable to have the intensities increase gradually toward white, or, what amounts to the same thing, to have each color neutralized as it loses light. That happens, constantly, in Nature.
152. Any two of the sequences which I have described as of the Horizontal, or even more than two, may be combined and used together.
| Seq. Lt and D, 3ds | ||||||
| Lt | R | O | Y | G | B | V |
| D | R | O | Y | G | B | V |
This scale gives us a variety of color-contrasts with one value-contrast. The colors are taken at the interval of the third. They might be taken at any interval up to that of the seventh, in which case we should have a contrast of complementary colors in two values, each color occurring in each value. The monotony of value which is inevitable in any single horizontal sequence is in the combination of two or more such sequences avoided. I have used the Red-Yellow-Blue triad in three and in five values with satisfaction. Each value represents a plane of light in which certain differences of color are observed.