This part of ISO 18314 specifies the method for determining the colour coordinates of a paint film. This method is only applicable to paint films that appear to be uniformly of one colour@ i.e. monochromatic@ when examined with normal vision. Paint films that do not completely hide a non-transparent substrate represent an opaque system and can be measured by using the procedure in this part of ISO 18314. Luminescent paint films@ transparent paint films@ and translucent paint films (for example for display or lamp glass)@ retroreflecting paint films (for example for traffic signs)@ and metallic paint films are outside the scope of this part of ISO 18314.