14 C.F.R. § 27.1397 Color specifications.
Title 14 - Aeronautics and Space
Each position light color must have the applicable International Commission on Illumination chromaticity coordinates as follows: (a) Aviation red—
y is not greater than 0.335; and z is not greater than 0.002. (b) Aviation green—
x is not greater than 0.440−0.320y; x is not greater than y−0.170; and y is not less than 0.390−0.170x. (c) Aviation white—
x is not less than 0.300 and not greater than 0.540; y is not less than x−0.040” or yc−0.010, whichever is the smaller; and y is not greater than x+0.020 nor 0.636−0.400x; Where yc is the y coordinate of the Planckian radiator for the value of x considered. [Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27–6, 36 FR 12972, July 10, 1971]
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart F—Equipment
Lights
§ 27.1397 Color specifications.