The following diagram will perhaps make this more clear. In this the three primary colors have been divided, each into two shades as indicated by the shade letters, R meaning red, B blue, and G yellow (German _gelb_) shades of the colors. By combining these colors as shown in the table, clean, clear shades will be given, whereas other combinations would be likely to spoil the shades. [Illustration: DIAGRAM OF MIXED COLORS Red B + Blue R = Violet Blue R + Red B = Violet Yellow R + Red G = Orange Red B + Orange = Red G Blue R + Green = Blue G Yellow R + Green = Yellow G Red G + Yellow R = Orange Blue G + Violet = Blue R Yellow B + Orange = Yellow R Red G + Violet = Red B Blue G + Yellow B = Green Yellow B + Blue G = Green] Take, for example, a special case, namely to turn a piece of crimson calico into a full rich scarlet. The crimson color contains a great deal of red, mixed with a little blue. If the piece were after-dyed, or “topped,” with yellow, even in small quantities, the result would probably be “muddy,” the yellow and blue together being in such strength as to seriously diminish the strength of the red, and make it more or less brown in shade. If, however, a reddish shade of orange were used for shading, instead of yellow, the red of the mixture would be constantly increased, while the yellow was “killing” the blue, i.e., turning it, with a little red, into grey; and before long the crimson, or bluish shade of red, would turn first into a true but softened red, with neither blue nor yellow predominating, and finally into a scarlet, with distinct traces of yellow. In making these Three-color Shades, therefore, the component parts of each dyestuff used must be studied; and in every case care must be taken to have the third color, whatever it is, added in such minute quantities as only to _soften_ and not to spoil the first shade. A teaspoonful, sometimes even a few drops of a solution of one strong color, will generally be enough to soften, and take the edge off, some gallons of dye-liquor containing a hard, clear mixture of the other two. A cupful, on the other hand, or even two or three tablespoonfuls might utterly spoil the bath and turn it into “mud,” as a dyer would say.