Colors and What They Mean
by Alan Rodgers

Reprinted from "INSULATORS - Crown Jewels of the Wire", June 1975, page 7

Greens, blues, yellows, purples, ambers: the colors of the rainbow and the colors of insulators. Insulators are very pretty, and they are found in a wide variety of these rainbow colors. However, insulators were not made in this wide range of colors to impress future collectors, although it may seem this way. Actually, in some cases, the colors had an important purpose. Different colors were used to designate different lines of different companies, different voltages, different circuits, or different types of service (signal, telegraph, power, etc.) on the same pole or the same cross arm. The color of the insulator made a convenient and fast method of determining this.

The popular Hemingray 19 style was considered to be the multipurpose insulator. It had any one of several uses, and many could be found on the same pole for different purposes. Thus the need for identification by colors. Hemingray advertised (also reprinted in Dictionary of Glass - Ceramic Insulators by Cranfill) their policy of having insulators available in blue, red, green, or brown glass for the purpose of identifying various lines. Only a slight extra charge for this, and all shipments would be made from the Muncie, Indiana, factory. Pyrex also offered brown for "markers". To date, no true red insulators have been found, to my knowledge. Several of the more recent styles have been found in a near red-amber color. So far, these may be as close to red as will ever be found. Gold or large quantities of selenium will produce red glass, along with a special lengthy process and great expense.

Generally, in electrical wiring, a white insulated wire indicates neutral, as distinguished from the black or "hot" wire. As an example, the white milkglass Maydwell 20, to indicate a neutral wire. However, it is not likely that the milkglass Hemingray E-14 B (CD 128) was intended for this purpose. It is common practice for many electric utility companies to place a white porcelain spool in the upper position of a secondary service rack to indicate neutral.

There are many variations of aquas, blues, and greens, with no significant color meaning, except, "That's the way they turned out." This endless variety is caused by variations in the glass batch. Many circumstances, including poor quality control, small inconsistent batches, different materials, the use of cullet, etc., produced this almost "no-two-alike" coloration. Cullet, old broken glass melted down, is added to give a certain strength to the glass. Many times, glass with unusual colors or traces of foreign colors may have been a result of this process. Note this in many Brookfield types. The McLaughlin 20's in an emerald green color may have been the result of using the green glass of a ginger ale bottle batch.

Many times, glass companies had trouble with decolorization, and strange colors resulted. Some collectors consider purple or S.C.A. (sun colored amethyst) to have been originally purple, straight from the mold. It is generally accepted that these were an attempt to decolorize, and that they turned purple due to the ultraviolet rays from the sun. The purple color had no specific purpose, except an unwanted result from a chemical change. Clear insulators were, among other things, intended to blend in with the background and sky and be more inconspicuous on the line.

The general use of specially colored insulators never became too popular, except in certain areas. On occasion, when repair work was needed on a line using specially colored insulators, in haste to restore service, any replacement from the truck would do. Even with the intention of returning with the proper color later, the line did not require too many of these replacements before the effectiveness of the concept of special colors was reduced.

A retired lineman friend of mine visited my home recently and was shown my collection. After looking it over, he remarked that he had never seen so many colors and never realized they were so pretty. Colors do have meaning. For insulator collectors, a good way to collect them; and for glass companies, a good way to sell them.