Saw trimmer is not compounded because there is no change in the commonly accepted sense of either word.
Color work is not compounded because the word color, by usage common in English, has the force of an adjective, and the words are used in their accepted sense. In other languages it would be differently expressed, for example, in French it would be oeuvre, or imprimerie en couleur, work, or, printing in color.
Presswork is compounded because it has a special and specific meaning. Good or bad presswork is a good or bad result of work done on a press.
Here as everywhere in printing the great purpose is to secure plainness and intelligibility. Print is made to read. Anything which obscures the sense, or makes the passage hard to read is wrong. Anything which clears up the sense and makes the passage easy to read and capable of only one interpretation is right.
INFLUENCE OF ACCENT IN COMPOUNDING
Some writers lay much stress on the influence of accent in the formation of compounds while others ignore it entirely. Accent undoubtedly has some influence and the theory may be easily and intelligibly expressed. It ought to be understood, but it will not be found an entirely safe guide. Usage has modified the results of compounding in many cases in ways which do not lend themselves to logical explanation and classification.
The general principle as stated by Mr. Teall is as follows:
When each part of the compound is accented, use the hyphen; laughter-loving.
When only one part is accented, omit the hyphen; many sided.
When the accent is changed, print the compound solid; broadsword. This follows the general rule of accenting the first syllable in English words.