Grating contrast sensitivity was measured using different colors and different grating orientations. The contrast sensitivity was highest when measured with green light, a little less when measured with red light, and lowest with blue light. The contrast sensitivity with blue light was relatively low compared with green and red light for high spatial frequencies, and relatively high for low spatial sensitivities. The so-called ‘Oblique effect’ was confirmed in this study, but a difference between horizontal and oblique gratings was only found in spatial frequencies higher than 18 cycles/degree. The present study, carried out on 20 persons, suggests that the inter- and intraindividual components of variance are smallest when measured with green light and vertically oriented gratings.