Fill a bucket with warm water.
Add dish detergent to the bucket until you have created suds.
Dip a clean cloth inside the bucket of water and detergent. Gently scrub the vinyl shutters. Work in one area at a time, removing any dirt, spiderwebs or other grime that is clinging to the shutters.
Scrub the shutters gently so that you do not damage them. Do not scrub them too roughly. If the yellowing is not removed, contact the shutters' manufacturer. Some types of vinyl shutters may be able to withstand chemical cleaners, but you should always make sure before using them as such cleaners can damage the shutters.