Several previous studies indicated that gins can increase the perceived color grade of cotton by as much as two grades and that Spotted and Light-spotted cotton could be improved to Light-spotted or White color grades. Consideration of the effect of each of the individual machines in a cotton gin in three recent studies indicated that the seed cotton cleaners did little to improve color but did improve trash grade. Further analysis showed that lint cleaners were the machines that improved the color of cotton. In these studies, grayness was increased by about 4.4 units. Much of the improvement in perceived color was attributable the removal of trash from the sample. Thus, lint cleaners must continue to be used to improve the color of cotton even in cases where little trash is present.