Yellow sticky traps are widely used against several insects in pest management. Up to, now, many studies on,effects of some factors such as trap site, vertical and horizontal positioning, and trap locations on capturing capacity of traps were,carried out, however, there is not much information on what hues of yellow color, brightness, and wave length should be. In this study, it is aimed to find out optimum trap color by determining the most attractive hues of yellow color for whitefly. Different hues of yellow color traps were made by sticking seven foils with different hues of yellow on fiberglass plate. The traps were hanged in three different organically grown tomato greenhouses in Seferihisar in 2004, in Urla in 2005 and in Balcova (Izmir-Turkey) in 2006. The trials were set up randomly block design with 5 replicates. Whitefly adults on both sides of the traps were counted after a week of trap hanging in the greenhouses. The results were analyzed statistically by one way ANNOVA. Although there was significant variation amongst the replicates, it was found statistically insignificant in terms of mean individual numbers of whitefly on different hues of yellow color traps.