Purpose. To evaluate the separate contributions of chromaticity and luminance to the perception of color from motion (Cicerone et al., Perception & Psychophysics, 1995). Methods. The stimulus consisted of 12 frames, each a 5° white square containing 900 randomly placed dots (each 3' of arc, red or green). Dots falling within a 1.2° circular region, assigned to the test, were of one chromaticity and of one luminance, either 4, 8, or 16 cd/m2. Outside the test region, dots were fixed at 8 cd/m2 and were either all red or all green. The test region was displaced vertically from frame to frame by reassignments of chromaticity and luminance while keeping dot locations fixed. When the frames were presented in quick succession (effective speed 3.3 deg/sec), the test region was perceived as a moving disk with color spreading within its boundaries. As chromaticity and luminance of the test dots and chromaticity of the surround dots were systematically varied, six color normals and one deuteranope were asked to rate apparent motion, subjective contour, and color spread on a 5-point scale and with color matching. Results. If the test and the surround were of different chromaticities and equiluminant, color normals perceived apparent motion and color spread, but no clear subjective contour. Adding luminance differences enhanced the perception of color spread and of a subjective contour. Luminance differences in the absence of chromaticity differences produced color spread. Adding chromaticity difference enhanced color spreading for all test-surround luminance contrasts. Under conditions with chromatic and luminance differences, the deuteranope performed as the color normals would if only luminance differences were present. Conclusions. Chromaticity differences in the absence of luminance differences between test and surround are sufficient for the perception of color from motion. Adding luminance can enhance perceived color spread.