Using a previously proposed quality-grading method, tests have been made of the effects of gain and delay inequalities between the luminance and chrominance channels of a 625-line NTSC-type broadcast colour-television system.50% favourable opinions are obtained with pictures impaired by a gain inequality, expressed as the error in chrominance-channel voltage gain, of ±56% 95% favourable opinions are obtained with a gain inequality of ±36%. For delay inequality the corresponding values are ±350 and ±210ns, respectively.