§27.1397 Colour specifications

Each position light colour must have the applicable International Commission on Illumination chromaticity co-ordinates 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 ‘yo–0.010’, whichever is the smaller; and ‘y’ is not greater than ‘x + 0.020’ nor ‘0.636– 0.400x’; Where ‘yo’ is the ‘y’ co-ordinate of the Planckian radiator for the value of ‘x’ considered.