THE ROLE OF DELINEATION AND SPATIAL-FREQUENCY IN THE PERCEPTION OF THE COLORS OF THE SPECTRUM

The observations of the spectrum made by Newton, Young, Wollaston and Helmholtz are approximated and accounted for. Increasing the number of delineations allows progressively more bands differing in colour to b e perceived, in addition to the three blocks of colour seen in the und elineated spectrum. The rate at which further delineation permits more colours to be observed decreases, however, so that up to 30 colours c an be perceived in the subdivided spectrum. The wavelength discriminat ion measurements agree well with previous data. Enhanced colour discri mination is shown to require luminance contrast transients containing only the first few Fourier harmonics.