(156) Here is a grayish green stuff for a dress, and the little girl who is to wear it asks what other colors she may use with it. First let us find it on our instrument, so as to realize its relation to other degrees of color. Its value is 6,--one step above the equator of middle value. Its hue is green, G, and its chroma 5. It is written G 6/5. (157) Color paths lead out from this point in every direction. Where shall we find harmonious colors, where discordant, where those paths most frequently travelled? Are there new ones still to be explored? (158) _There are three typical paths: one vertical_, with rapid change of value; _another lateral_, with rapid change of hue; and a _third inward_, through the neutral centre to seek the opposite color field. All other paths are combinations of two or three of these typical directions in the color solid. +Three typical color paths.+ [Illustration: Fig. 25.] (159) 1. The vertical path finds only lighter and darker values of gray-green,--“self-colors or shades,” they are generally called,--and offers a safe path, even for those deficient in color sensation, avoiding all complications of hue, and leaving the eye free to estimate different degrees of a single quality,--color-light. (160) 2. The lateral path passes through neighboring hues on either side. In this case it is a sequence from blue, through green into yellow. This is simply change of hue, without change of value or chroma if the path be level, but, by inclining it, one end of the sequence becomes lighter, while the other end darkens. It thus becomes an intermediate between the first and second typical paths, combining, at each step, a change of hue with a change of value. This is more complicated, but also more interesting, showing how the character of the gray-green dress will be set off by a _lighter_ hat of Leghorn straw, and further improved by a trimming of _darker_ blue-green. The sequence can be made still more subtle and attractive by choosing a straw whose yellow is _stronger_ than the green of the dress, while a _weaker_ chroma of blue-green is used in the trimming. This is clearly expressed by the notation thus: Y 8/7, G 6/5, BG 4/3, and written on the score by three dots and their chromas,--7, 5, and 3 (see Fig. 23). (161) 3. The inward path which leads by increase of gray to the neutral centre, and on to the opposite hue red-purple, RP 4/5, is full of pitfalls for the inexpert. It combines great change of hue and chroma, with small change of value. (162) If any other color point be chosen in place of gray-green, the same typical paths are just as easily traced, written by the notation, and recorded on the color score. +These paths trace sequences from any point in the color solid.+