The Body parameter is a 3 element, comma delimited array holding the settings used for defining if the web page should refresh, what the background color is and if a symbol should flash.
By using the Refresh element you can tell the API that the web page should automatically refresh. Both the Suggested Pickup and Suggested Pickup Period are used to determine when the page will actually refresh. These two values can be seen either in the HTML Headers returned or in the raw XML from NOAA's National Weather Service. Allowed values are either "true" or "false".
By using the Color element you can tell the API what color to send back as the body background. Any valid hex triplet is allowed. Do not send the "#", however. A useful tool to help you is the HTML Color Picker.
By using the Blink element you can tell the API what symbol you would like to have flash. Allowed values are ":", "@", "\", "-", ".", "_", "~", "!", "$", "'", "(", ")", "*" and ";"