Redefining White Light Chromaticity Boundaries for Aviation
The LRC conducted a human factors investigation of the boundaries in chromaticity space that people perceive as white and recommended new aviation white boundaries that were independent of the color limitations of incandescent sources.
The research indicated that the current color boundary of aviation white extends too far towards the "yellow" region. On the other side, the blue boundary of aviation white may be too conservative. Based on the results of this study, the CIE's recommendations, and the available literature, the LRC recommended:
- The yellow boundary of aviation white should be moved to x = 0.440 (from x = 0.540). This change would help limit confusion between white and yellow signal colors.
- The blue boundary of aviation white should be moved to x - 0.320 (from x = 0.350). This would allow some relatively high CCT LED sources to be used (up to 6000k).
- The boundaries in the y-direction should be expanded to full cover the white LED chromaticity bins specified by ANSI C78.377.
Federal Aviation Administration