Gray is what most people seem to use because it matches well and is more commonly available. Be careful if you order the "aluminum" color since Vulkem comes in three different colors of aluminum. The three colors of "aluminum" Vulkem 116 are: 1-Aluminum, 2-Aluminum Stone, and 3-Anodized Aluminum. Also there is a color "Limestone" that is a pretty close match. I would suggest visiting (tremcosealant.com
) for more info on this. On the site you can find local distributors by entering your zip code then you can go look at samples of the colors for yourself. I checked and it shows a distributor near you in Doraville, GA . FWIW I prefer to use TremPro 635 "gray" available from Vintage Trailer supply because it is smoother than Vulkem. Sikaflex 1a is also a excellent urethane and it is smooth like the TremPro.