White: A colour which has no readily discernible hue (2-1-440).
Note: A surface colour is considered to be "white" if its spectral luminance factor is approximately independent of wavelength and exceeds a value of about 0.7.
Red: In general, the hue of any monochromatic radiation in the visible spectrum at a wavelength greater than about 610 nm under conditions of photopic vision.
Green: In general, the hue of any monochromatic radiation in the visible spectrum at a wavelength between about 495 and 550 nm under conditions of photopic vision.
Note: These terms, when applied to colours of signal lights or to colour filters or surface colours (in the latter two cases for a specified or assumed reference illuminant), are defined by specifications of chromaticity limits established by various organisations.
Recommended values of these limits for application in all forms of transport service have been agreed internationally and are given in Reference: C.I.E. Publication No. 2 (W-1.3.3), 1959.
A "Recommendation for the Standardisation of Colours of Lighted Aids to Navigation" has been published by I.A.L.A. (April 1968).
Certain countries publish their own mandatory regulations for colour limits which lie within the boundaries of the Reference: C.I.E. recommendations.
Thus, in Great Britain, regulations for colour light signals and colour filters for all forms of transport, including maritime transport, are published in British Standard BS1376 1953.
In the U.S.A., similar regulations are given in the "U.S. Standard for the Colors of Signal Lights", National Bureau of Standards Handbook 95, August 1964.
In Germany, similar regulations are given in DIN 6163 Sheets 1 to 8, September 1959 and, for colour for traffic signals, DIN 6171 (May 1970)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
Number of cells
Level (technician training - WWA)
Latitude (in degrees)
German steel grading
Deutsches Institut für Normung, the German Institute for Standardisation
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM