This SAE Standard defines and provides a means for the control of colors employed in motor vehicle external lighting equipment, including lamps and reflex reflectors. The document applies to the overall effective color of light emitted by the device in any given direction and not to the color of the light from a small area of the lens. It does not apply to pilot, indicator, or tell-tale lights.
The specification for green was replaced with the recommendation for green color limits from FAA document DOT/FAA/TC-TN12/61, October 2012 “Nonincandescent Source Aviation Signal Light Colors”. This study recommended new green color limits to accommodate the increased use of LED sources and minimize the possibility of misidentification of green signals. The RESTRICTED BLUE green and violet color boundary equations were modified to harmonize them with the blue UNECE R65 color boundary equations. The SIGNAL BLUE violet boundary equation was changed to the new RESTRICTED BLUE violet boundary equation so that the violet boundary of both the RESTRICTED BLUE and SIGNAL BLUE color spaces would be the same. The coordinates of the color boundary vertices were added to aid in the plotting of the chromaticity boundary regions. The reference to SAE J578 JUN1995 in 2.1.1 and Appendix A.3 was removed to eliminate the document referencing itself. The reference to HS-34 was removed because it is no longer available. The statements concerning the usage of Signal Blue and Restricted Blue were moved to the more appropriate location in appendix A.2 “Color Application”, Signal Blue is used in applications where the viewer may misidentify the blue signal as a color other than blue and this will have little or no effect on their response to the signal. Restricted Blue is used in applications where having the viewer identify a blue signal as blue is important in obtaining the desired response from the viewer. Section 2.2 Related Publications was added and the document IES TM-27-24 was added to the Related Publications section because it is the industry standard method for the transfer of spectral data. The suffix was removed from ASTM 308 to make the document reference version independent.