In every field of science and technology, there are standards which are agreed-upon procedures. These are developed by individual trade associations and professional societies, and refer to the procedures and products of these groups. One such large group is the American Society for Testing & Materials (ASTM) which has developed thousands of standards through the operation of about 140 various committees. To insure impartiality, ASTM requires that the voting members of each committee, and sub-committee thereof, must have a majority users and public interest personnel rather than manufacturers/sellers. The manufacturers cannot dominate the development process, nor can the standard be made so restrictive as to enable only one entity to comply.

Another group, The American National Standards Institute (ANSI), is a voluntary standards coordination organization which establishes procedures and policies for standards development by the trade associations and professional societies, similarly to ASTM. It also acts as the point of contact between the United States and other international standards groups such as ISO and IEC.

There are various types of standards:

- “Guides” provide general information about a field of interest.
- “Practices” are more specific and lead the novice towards the standard he seeks.
- “Specifications” provide precise information with which a product or discipline must comply, including tolerances.
- “Test Methods” instruct the user on how to test for compliance.

COLOR CODES

There are two (2) color codes widely used in the United States. These same codes, or similar ones, are also used in many other countries. A specific meaning is attached to each color in the code. The colors are displayed on signs and labels, often in concert with standardized words and symbols. The number of colors for the codes must be limited to eight or ten in order to be readily distinguishable from each other and accurately identifiable under poor visibility conditions and for a short time, as from a moving vehicle.

1- ANSI Standard Z535.1 Color Code:

Safety :These are a series of related standards identifying safety hazards using colors, signs and symbols which appear on labels, placards, machinery moving parts, toxic substance containers, etc., to alert as to their location, nature and severity. These colors are specified in appropriate ways, with tolerances for each, and test methods references for meeting the standard. They are: Red, Yellow, Green, Blue, Orange and Purple.

Other Z535 standards (.2 through .6) describe the use of these colors and symbols, along with Signal Words Danger, Warning, and Caution, identifying three specific degrees of hazard.

2- Department of Transportation (DOT) Color Codes.

Office of Hazardous Materials (HazMat) Placard Colors: Around 1975, this office was formed for the purpose of identifying various hazardous materials (flammables, radioactives, toxic wastes, etc...) in transit. To implement the ensuing regulations and identify the materials to the public, a series of vivid colors was selected to be displayed on 14"x14" diamond shaped placards placed on the carriers (i.e., trucks and railroad cars) transporting them.
Since the ANSI Safety colors series was already in existence for the same purpose, there was clearly no need to come up with a new set. Thus DOT adopted those same colors for their HazMat color standards.

Federal Highway Administration (FHWA) Highway Sign Colors: Soon after the automobile came into widespread use, DOT adopted another series of high visibility colors for signs identifying various situations and landmarks for the motoring public:

Red background with white lettering, on distinctive octagonal and triangular shapes, for STOP and YIELD signs.

Yellow background with black lettering for CAUTION signs of several types. This same yellow is also used for highway paint striping.

Green background with white lettering for signs announcing upcoming highway destinations, general and location specific highway exits, other intersecting major Highways and Routes.

Blue background with white lettering to announce public service landmarks for gas, food, lodging and hospitals.

White with black lettering for Regulatory Signs (i.e., speed limits).

Orange with black lettering for signs identifying construction zones. These were specified years later and when determining the precise position of the orange and its tolerances, it was clear that the red and yellow hues were a bit too close together to comfortably insert it between them so it was done as best as possible to avoid a major change to shift the red and yellow.

Brown signs with white legends, for Parks and historical sites.

Yellow/green with black lettering for school crossing zones was specified in recent years and are also fluorescent to increase their conspicuity to enhance safety. However, we do not manufacture or carry these specific charts.

FAA AVIATION ORANGE FOR TELECOMMUNICATIONS TOWERS

FCC Rules and Regulations Part 17 as well as corresponding FAA rules, require that towers be painted a specific orange color. The intent of these rules is to insure that towers are sufficiently conspicuous so that aircraft crews will have no difficulty in seeing and avoiding them. To assist with compliance of these regulations. A chart was conceived which displays the permissible color range of the orange deviations from the standard. By visually comparing the chart to the tower by way of the window on each page, one can determine whether it is necessary repaint the tower or formulate new paint mix for the next application.

COLOR QUALITY CONTROL

Instrumental color quality control involves either a spectrophotometer or a tristimulus colorimeter. These instruments, especially the former, are rather expensive but are preferred when color tolerances are tight and many measurements are required, especially if the specimens to be measured can brought to the instrument rather than resorting to the portable ones which are less precise and somewhat limited in their versatility. Color measuring instruments are widely used in plants where pigments, paints, plastics, dyes, textiles, paper and other colored products are made.

Visual color quality control is often preferred when a target’s tolerances are broad, the number of measurements is relatively few, and when it may be necessary to measure specimens in a large number of locations. Such situations include evaluating the results of weathering on highway, safety and hazard warning signs, as well as communications tower markings, which have liberal specified tolerances easily determined visually.