The below plug housing connector is made of Nylon, but this can happen to other plastics as well. The natural nylon displays white color in most case (different supplier’s resin may have a little difference, white or dark white). As there are some heat stabilizer which contains Cu² ion, the Nylon changes to green color after absorbing moisture. Also the stored period will affect the nylon housing change to yellow.This discoloration does not affect the form, fit and function of connector. It meets the product specifications.