Spot color Spot color In offset printing, a spot color or solid color is any color generated by an ink (pure or mixed) that is printed using a "single run", whereas a process color is produced by printing a series of dots of different colors. The widespread offset-printing process is composed of the four spot colors cyan, magenta, yellow, and key (black) commonly referred to as CMYK. More advanced processes involve the use of six spot colors (hexachromatic process), which add orange and green to the process (termed CMYKOG). The two additional spot colors are added to compensate for the ineffective reproduction
Early American editions of The Hobbit 14th impressions come in a variety of colors. Generally all the books from one printing are bound in the same color, but exceptions may have been found, perhaps when bindings intended for one printing were left over and found use at the beginning of the next printing. Hence the color of the covers cannot conclusively identify a book. The 6th impression's blue-green is medium light and distinctly blue. The 7th impression's khaki binding, on the other hand, shows no hint of blue or green. Its color is considerably darker than the 10th through 12th impressions. The rust color of the